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Evolution of Insects in terms of the Implicate and Explicate Orders.

Evolution of the flight-function in insects

Part IV

Description of types of flight-devices and flight in insects

( Shield-wingedness )

Most expressed examples (Coleoptera) of the type :

Figure 1 :  Cybister  lateralimarginalis, 30-32 mm. Aquatic beetle, recent. Family Dytiscidae, Order Coleoptera.
(After SEVERA, in Thieme's insektengids voor West- en Midden-Europa, 1977)

In the Order Coleoptera (beetles) the forewings have been transformed into stiff shields. Such a shield or cover we will call  elytron (pl. elytra), to distinguish it from a  tegmen (pl. tegmina) - the stiffened forewing in cockroaches, grasshoppers, bugs, ect. The hindwings, if present, are always membranous with clear venation. So when we speak of the "wings" of beetles we mean the hindwings.

Figure 2 :  Right elyrtron of  Asiocoleus  novojilovi Rohd., Length of elytron 7.4 mm., width 1.6 mm. Family Asiocoleidae, Order Coleoptera.  Lower Permian of Basin of Kuznets, Siberia.  (After ROHDENDORF et al., 1961)

Figure 3 :  Elyrtron of  Cytocupoides  elongatus Ponom., Length of elytron 4 mm. Family Permocupedidae, Order Coleoptera.
Upper? Permian, Basin of Kuznets, Siberia.  (After PONOMARENKO, 1969)

Figure 4 :  Schematic drawing of the venation of the elytron, considered to be original for the beetles of the family Tshekardocoleidae (lower permian). Continuous lines indicate chief veins. Wavy lines indicate intercalated veins. Dashed lines indicate assumed chief veins not found in known beetles.  (After PONOMARENKO, 1969)

Figure 5 :  Sylvacoleus  sharovi Ponom., Tshekardocoleidae. Coleoptera.  Reconstruction.  Lower Permian of the Ural, Russia.
(After PONOMARENKO, 1969)

Figure 6 :  Scheme, drawing all veins found in the wings -- the hindwings of course -- of beetles (Coleoptera).
(After PONOMARENKO, 1969)

Figure 7 :  Wings of beetles (Coleoptera).
       Upper image :  Hypothetical general plan of venation and folds. (After FORBES, 1922).
       Middle image :  Prolixocupes  latreillei Solier. (After FORBES, 1926)
       Bottom image :  Micromalthus  debilis Leconte. (After FORBES, 1926)
       Convex folds indicated by punctuation, concave folds by dashed lines.
       (In PONOMARENKO, 1969)

Figure 8 :  Wings of beetles (Coleoptera).
       Upper image :  Priacma  serrata Leconte. (After ATKINS, 1958).
       Middle image :  Cupes  capitatus F. (After FORBES, 1922)
       Bottom image :  Omma  stanleyi Newman. (After TILLYARD, 1926)
       (In PONOMARENKO, 1969)

Figure 9 :  Folding of the wings of beetles (Coleoptera).
       Upper and lower image :  Priacma  serrata Leconte.
       Middle image :  Micromalthus  debilis Leconte.
       (After van EMDEN, 1932, in PONOMARENKO, 1969)

Figure 10 :  Catadromus  lacordairei Bd., Carabidae (Coleoptera), Australia.  Elytron and wing
       ap - apex.  hm - shoulder margin.  lm - lateral margin.  in - intervals.  pn - rows of points.  scm - margin coming close to scutellum.  sm - seam margin.  st - rib.  ob - elongate cell (oblongum).  (After TILLYARD, in ROHDENDORF, 1949)

Description of the type
Morphological features
There is a sharply expressed heteronomy in the pairs of wings. Mesothorax significantly smaller and weaker developed as compared to the powerful metathorax. Muscular apparatus also markedly different in these thoracic divisions. Metathoracic muscles present in a large number of pairs and stronger developed. Forewings markedly stiffened and transformed into firm, more or less hard coverings -- elytra. Their venation is rudimentary or undergoes far-reaching change, and, where detectable at all, does not show aerodynamic specialization. The hindwings are membranous and are the sole organs of flight, creating traction. They are large, and, as a rule, are, in resting position, folded, along longitudinal and transverse folds, under the forewings, the elytra. The venation of the hindwings is aerodynamically specialized, showing a marked degree of costalization. More rarely the venation is fan-like with a series of straight longitudinal veins. Size of body very variable -- from minute, 2-5 mm, insects up to 50 mm and larger.
[To this type (elytropterygia) do belong first of all - the beetles (Coleoptera), and, further, winged stick insects (Phasmato(i)dea), some Orthoptera-saltatoria (grasshopper-like insects), some Blattaria (cockroaches) (Diplopteridae), and the fossil permian Protelytroptera. Further some cicadas (Cercopidae) and the fossil Scytinopteridae and Prosbolopsidae, and some others, do belong to this type (see below). Obviously it is the beetles where elytropterygia is most strongly developed. And even their highly modified elytra show that they have evolved from true (membranous) forewings with the usual venation. To show this, we quote a page from the book of PONOMARENKO, Istoritjeskoje razwitije zjestkokrilich-archostemat (Historical development of the Coleoptera-Archostemata), 1969, pp. 35 (the Suborder Archostemata consists of the recent families Cupedidae and Micromalthidae, and a number of fossil families such as the Tshekardocoleidae) ] :
The elytra in Tshekardocoleidae (lower Permian) are markedly longer than the abdomen. In the majority of Archostemata they do not run beyond its apex. In Micromalthus they by far do not reach it. Many beetles-archostemata possess strongly broadened epipleura laterally, and the elytra of many archostemata are of a meshwork structure, and [having] a venation consisting of chief and intercalated veins. The chief veins usually are markedly thicker than the intercalated veins, but in Taldycupedidae [upper Permian and Triassic] they are of similar structure. The intercalary veins and cross-veins originate from the archedictyon [an ancient original dense network of very small cells between the main veins]. The original configuration of the cross-veins was irregular, and the intercalary veins followed a zig-zag course, and after this the cross-veins ran through the regular interspaces perpendicular to the longitudinal veins, and the intercalary veins became straight veins similar to the chief veins. The largest number of chief veins and their branching is found in the elytra of Tshekardocoleidae. Here we may count up to 14 chief veins (see Figure 4, above ) :  Subcosta (SC), forming the line of bending of the epipleura, Radius (R), usually with a short forwardly curved branch, up to three branches of the Radial Sector (RS1, RS2, RS3), Media (M), two Cubital veins (CuA, CuP), and three Anal veins (A2, A3, A4) [A1 having been lost, see below]. M and CuA may begin with a common stem.
In the course of evolution the number of veins became reduced and became to run parallel to the [longitudinal] axis of the elytron, such that in  Cupes  were preserved only three complete chief veins -- M, CuA, A2, and a shortened A3.  A1 is not, in the form of a clearly expressed chief vein, found in any beetle, but in the majority of Tshekardocoleidae the field between the veins taken by us as CuP and A2, proximally is markedly broadened, having close to the base of the elytron 4-5 rows of cells. Such a form is usually possessed by a field in which a chief vein has been reduced. Therefore, the first clearly expressed anal vein is taken by us to be the second, and not the first.  A3 is in all known beetles strongly shortened, A4 forms a seam edge, and cells behind it may be found only in the most primitive Tshekardocoleidae. Beetles of the family Ademosynidae (Permian-Cretaceous) had elytra with 8-10 punctuated grooves. The elytra of the majority of schizophoroid archostemates are smooth on their upper side, with many preserved traces of cells on the underside. In many, apparently aquatic forms the elytra had on their underside at the external edge a projection. This projection hooked, when the elytra were closed, with a corresponding projection on the dorsal part of the metepimeron, forming a lock, preventing the elytra from being lifted up by the air in the subelytral cavity. In fossil remains of beetles this projection appears to look like a depression, and it was described as the "split" (Rohdendorf et al., 1961).
(End of quote from PONOMARENKO)

Functional features
The fore- and hindpairs of wings act completely differently in flight. In the representatives of this type the forewings, the elytra, do not perform beats, only being lifted and motionlessly projecting sideways during flight. In some forms the elytra not even perform this movement [of just lifting themselves up], being all the time [whatsoever] motionless :  the hindwings push themselves outward and spread out from under the elytra thanks to the presence of a special slit in their anterior margin [as we can see it in, for instance, the golden beetle, Cetonia  aurata, where indeed the elytra remain closed during flight]. Wing-beat frequency is insufficiently studied, and, apparently, rather high. Thus for lady beetles, Coccinellidae, has been given 69 beats/sec, and for softbodied beetles, Cantharididae, 91 beats/sec. Absolute speed of the representatives of elytropterygia (shieldwingedness) is hardly investigated. Data are known of the corn-beetle -- 2.2-3 m/sec, the dungbeetle -- 7 m/sec, and of the leaf-gnawer Agelastica  alni -- 0.9 m/sec. Governability is quite variable in different representatives of the type, and usually is low. Only in some most progressive representatives of shield-wingedness -- the beetles -- flight has acquired great governability. Load exerted on a unit of wing-surface area is rather high :  such are the data on the corn-beetle -- 0.0820 gr/cm2 and on the dung-beetle -- 0.1525 gr/cm2.
The biological meaning of flight in the type of shield-wingedness (elytropterygia) is quite variable. To the great majority of representatives flight is an important locomotory function and usually is connected with looking for food and with distribution. In these, flight does not occupy much time during the period of active life. It is just for a short episode. Only in a few representatives of the type flight does play the most important role in their life, being the chief way of locomotion.

Differentiations, connections, and representatives of the type.

Shield-wingedness is a widely distributed and differentiated type of flight-device. The sources of the formation of shield-wingedness are rather diverse. The basic type out of which shield-wingedness began to form, undoubtedly was blattopterygia. Another important source consisted of straight-wingedness (orthopterygia) and neuropterygia. And also, undoubtedly, peculiar forms of shield-wingedness originated on the basis of regressive development of heteropterygia. In all these cases the stiffening and shortening of the forewings, elytra, determined the appearance of features of shield-wingedness (elytropterygia). In addition, the different sources of the formation of this type, together with further differentiation, has determined its diversity.

Subtypes of elytropterygia

1.    Orthelytropterygia
Most primitive are derivatives of orthopterygia, in which the forewings were strongly shortened, while the hindwings had not yet acquired markedly expressed costalization, preserving the fan-like shape and very rich venation. Such a kind of structure may be distinguished as a special subtype - elytropterygia-of-orthoptera or [equivalently] orthelytropterygia (orth-elytro-pterygia), to which belong winged stick insects (Phasmatoidea)and some Orthoptera-Saltatoria, for example Tetrigidae and Tridactylidae. See next Figures.

Figure 11 :  Wings (elytron and wing) of  Xeroderus  kirbyi Gray., Bacteriidae (Phasmatoidea [Phasmatodea, Phasmida] ), Australia.  Length of wing 65 mm.  (After HANDLIRSCH, in ROHDENDORF, 1949)

Figure 11a :  Calvisia  atrosignata Stal.  Phasmatodea. Recent.  (After BRUNNER, 1893 in SHAROV, 1968)

Figure 12 :  Wings of orthopteroids with a shortened anterior pair.
Left image :  Tetrix sp., Tetrigidae, holarctic. Elytron and wing. Length of latter 10-13 mm.
Right image :  Tridactylus  variegatus Latr., Tridactylidae, Europe.

Figure 13 :
Left image :  Tridactylus  variegatus Latr., Tridactylidae. Recent. (After BJEI-BYENKO, 1964).
Right image : Fore and hindwing of the same species. (After SHAROV).
(In SHAROV, 1968)

Figure 14 :
Upper image :  Tetrix  depressa Bris., Tetrigidae. Recent. Fore- and hindwing. (After SHAROV)
Bottom image :  Tetrix  nutans Hag., General view of the insect. Recent. (After BJEI-BYENKO and MISCHENKO, 1951)
(In SHAROV, 1968)

2.    Protelytropterygia
A second, also little-specialized example of shield-wingedness is represented by derivatives of blattopterygia, in which the forewings already have acquired the form of true stiff elytra, having preserved [in fact, "already having"], it is true, a reduced venation, while the hindwings had worked out the ability to fold along a transverse seam, and preserving a still fairly rich venation. This subtype, ancient elytropterygia, or [equivalently] protelytropterygia (prot-elytro-pterygia), is illustrated by the cockroaches of the family Diplopteridae, and the fossil permian Protelytroptera. See next Figures.

Figure 15 :  Diploptera  dytiscoides Serv., Diplopteridae, Order Blattaria, Australia. Body-length 13.5 mm.

Figure 16 :  Protelytron  permianum Till., Protelytridae, Order Protelytroptera. Permian of America. Reconstruction.

3.    Hemelytropterygia
Special forms the type shield-wingedness has in the groups being derivatives of  neuro- and orthopterygia  and also of  heteropterygia, in which the forewings were strongly stiffened [but not so strongly as in eu-elytroptererygia], and the hindwings acquired a broadened shape, provided with longitudinal veins, configured radially, but in significantly lower numbers than in true orthopteroids. To this subtype, hemelytropterygia (hemi-elytro-pterygia), do belong [first of all] some cicadas (Cercopidae [next two Figures],

Figure 17 :  Cercopis  vulnerata, Cercopidae, Order Homoptera. Recent. 9.5-11 mm.
(After SEVERA, in Thieme's insektengids voor West- en Midden-Europa, 1977)

Figure 18 :  Wings of  Aphrophora  maritima Mats., Cercopidae, Order Homoptera. Recent. Europe.

. . . and the fossil Scytinopteridae (next three Figures),

Figure 19 :  Wings of  Scytinoptera  reducta Mart., Scytinopteridae, Order Homoptera. Permian of the Archangelsk region, North-western Russia.  (After BECKER-MIGDISOVA, in ROHDENDORF, 1949)

Figure 19a :
Left image :  Permojassus  australis Till.  Family Scytinopteridae, Order Homoptera. Upper Permian of Warner's Bay. New South Wales, Australia. Tegmen. Length 6 mm. Width 2.5 mm.
Right image :  Permojassus  australis Till.  Family Scytinopteridae, Order Homoptera. Upper Permian of Warner's Bay. New South Wales, Australia. Hindwing. Length 6 mm. Width 2.6 mm.   Anal area ample but not expanding beyond the contour of the rest of the wing.
Types :  Holotype tegmen, Specimen No. 54b, in Mr. Pincombe's Collection found by him at Warner's Bay, May 6th, 1923.  Heautotype hindwing, Specimen No. 56 in the same collection, found at the same place and time in the same piece of rock not far from the tegmen. Both specimens are on a rather dark grey chert and only moderately well preserved, but with careful lighting all the veins can be made out.
(After TILLYARD, 1926)

Figure 19b :
Top image :  Orthoscytina  mitchelli Till.  Family Scytinopteridae, Order Homoptera. Upper Permian of Belmont, New South Wales, Australia. Tegmen. Length 10 mm. Greatest width 3.4 mm near apex.
Bottom image :  Orthoscytina  quinquemedia Till.  Family Scytinopteridae, Order Homoptera. Upper Permian of Warner's Bay. New South Wales, Australia. Tegmen. Length 8 mm. Greatest width 2.6 mm near apex. The small circles probably indicate air or gas bubbles present during fossilisation.
(After TILLYARD, 1926)

. . . Prosbolopsidae),  further [do belong to the subtype hemelytropterygia] the fossil  Prosbolidae  (see next two Figures) :

Figure 19c :  Prosbole  hirsuta Koken.  Family Prosbolidae. Order Homoptera. Tegmen (hemelytron). Length about 4.6 cm. Upper Permian, Kama River, Russia.  (After HANDLIRSCH, in TILLYARD, 1921)

Figure 19d :  Permoglyphis  belmontensis Till.  Family Prosbolidae, Order Homoptera. Upper Permian of Belmont, New South Wales, Australia. Tegmen, length 9.4 mm., greatest breadth 3.6 mm.   n - nodus, tg - tegula.
From the nodus (n), a faint, curved, transverse line divides the tegmen as far as Cu2 into a somewhat roughened, granulate basal portion and a very smooth distal portion.
(After TILLYARD, 1926)

[although, in fact, as a result of the incipient division of the tegmen into a coriaceous and a membranous part, the Prosbolidae do foreshadow heteropterygia, or may already truly representing this type. And indeed, we take them to represent the subtype proheteropterygia of the type heteropterygia.]

. . . and [also belonging to the hemelytropterygian subtype], probably, certain booklice (Psocoptera), namely the extinct Sphaeropsocidae, see next Figure,

Figure 20 :  Sphaeropsocus  kuenowi Mast., Sphaeropsocidae, Order Psocoptera. Baltic amber.

. . . and, finally, some bugs (Hemiptera) (Helotrephidae, Pleidae).

To the listed representatives of the present subtype (hemelytropterygia) we can add another recent but primitive Australian cercopid and a specialized representative of the group centered around the Scytinopteridae from the Triassic of Australia :

Figure 20a :  Venation of tegmen of  Philagra sp.,  Cercopidae, Order Homoptera. Recent. From Mount Tambourine, Queensland, Australia.  (After TILLYARD, 1919)

Figure 20b :  Tegmen of  Ipsvicia  jonesi Till.,  Ipsviciidae, Order Homoptera. Upper Triassic, Ipswich, Queensland, Australia.  Length of tegmen 14.2 mm, greatest width 5.6 mm.  Veins of the clavus distinct, those of the rest of the tegmen faint, becoming very indistinct distally, so that their terminal branchlets cannot be made out with certainty (This is not due to faulty preservation, but is the actual condition of the venation in the insect, as in the case of Philagra (see Figure 20a )  and other Fulgoroids, in which the membrane of the tegmen has become much thickened). (After TILLYARD, 1919)

The establishment and meaning of this subtype is, in a certain degree, provisional. Things are namely such that in the original forms of hemelytropterygia an active role during flight of the forewings is characteristic. It is perfectly possible that stiffening and transformation of the forewings in the majority of these insects is merely a process of development of apterygia, i.e. reduction of the flight-function, and thus totally not the working-out of one or another special type of flight and wings. Let us recall that of shield-wingedness the loss of flight-movements by the forewings is characteristic.

Before we move on to the text of Rohdendorf describing the next subtype of elytropterygia, viz., eu-elytropterygia, it is worthwhile to dwell a little longer upon the fossil (permian-triassic) family Scytinoptyeridae and the recent Cercopidae (their wings belonging to the present subtype, hemelytropterygia, of elytropterygia), and also a little on the fossil (permian) families Archescytinidae (as to their wings belonging to the type of  neuropterygia  and Prosbolidae (as to their wings belonging to the subtype proheteropterygia of the type of  heteropterygia  (all four families belonging to the Order Homoptera).
Although of tough consistency, the forewings of the representatives of the family Archescytinidae nevertheless should be taken as membranous. They have no true shielding function. The forewings of Scytinopteridae and of Cercopidae, on the other hand, are completely hardened, i.e. from base to apex. The representatives of the family Prosbolidae, finally, have their forewings more or less divided into a chitinized basal half and a membranous distal half (which tendency is completed in the Heteroptera). As far conjectured, the representatives of all fossil homopterous families just mentioned hold their wings (at rest) roof-like over the abdomen, like the recent  Cercopidae  (and, to my knowledge, most recent Homoptera, in contrast to the Heteroptera).
According to BECKER-MIGDISOVA, 1948, the forewings (tegmina) of the representatives of the family Scytinopteridae (Permian, Triassic) apparently have just a shielding function. They are completely sclerotized (the distal part, as well as the proximal part, is covered by rough tubercles and warts. Often, as a result of the strong sclerotization, the venation is unclear). So indeed in the tegmen of the representatives of this family there is no division into a proximal hardened and a distal (more or less) membranous part, meaning that the wings in this family do not belong to the type  heteropterygia, but, indeed, to the subtype hemelytropterygia of the type elytropterygia. The recent Cercopidae have still preserved the basic plan of venation and other characteristics of the tegmina (forewings). But individuals of the same species might significanly vary as to venation and coloring of their tegmina.
In our noëtic theory of organic evolution -- as presented mainly and provisionally on Fifth Part of Website -- we hold that all individual variations having taken place in the morphology of the individuals of the same organismic species are due to (local and individual) factors residing exclusively in the Explicate Order (which Order is precisely and exclusively the domain of materiality, individuality, and of spatial localities), while all species-constant characters (morphological, physiological, as well as behavioral) are developed and determined in the Implicate Order (in which no individuals, individual cases or factors do exist), and, after projection, materially appear in the Explicate Order. Further, we take it that all organismic species are such that they have not evolved (whether in the Implicate or Explicate Order) from each other in any way whatsoever, in other words we take the organismic world to be entirely polyphyletic, with the  species  (not the individual) as the unit-entity. As to insects, we further assume (as just a hypothesis) that, although embedded in, and influenced by, a functional context, the venation of the wings of insects generally is non-functional. Therefore, when in the Implicate Order (see the theoretical discussion in  Part II of the present series of documents) a given original immaterial form develops into a strategy (in order to be able to exist materially in the Explicate Order), striving thereby, however, to preserve its original identity, the result will be, the preservation of the non-functional characters originally making up the content of such a form, while new functional characters are being added to the original core. If then the  p a t t e r n  of wing-venation of an insect is originally non-functional (except with respect to more or less evenly strengthening the wing-membrane), then it will be expected to persist despite the changes involved in the transformation (in the Implicate Order) of the original immaterial form into a fully-fledged strategy (still being immaterial, in the form of some sort of description). But of course, it may happen in some cases that the original venational scheme, as such representing at least a part of the content of the original immaterial form, is, because of functional factors, partly, or even completely, 'overwritten', overwritten that is, by functional characters, not belonging to the content of the original immaterial form but to the adventive elements of the strategy, or (overwritten) by characters belonging to neither. There are also cases in which the hindwings have been reduced to mere rudiments and the forewings, having lost their original flight-function, are just shields. In such cases we may expect there to be no or, at least, less of a control (i.e. damping) of influencing factors in the Explicater Order that may change the venation of such wings in the next generations. So here great individual variability is to be expected.
Indeed, there exist two main factors causing a partly or completely 'overwrite' of the original venational pattern (or of other morphological features in the representatives of a given organismic species, [features] expressing the original immaterial form, now materialized) :  (1) the material (i.e. physical) factors in the Explicate Order, resulting in the well-known individual variation within existing organismic species, and thus also the individual variation of the wing-venation in such species, and (2) those adventive functional and species-constant characters that do suppress part (or the whole) of the original venation. The action of these factors thus results to obscure the original immaterial form insofar as it was represented in the non-functional wing-venation (or/and in other non-functional characters of the organismic species concerned).

In the forewings (tegmina) of the representatives of the homopterous families Archescytinidae (lower permian), Scytinopteridae (upper permian, upper triassic), Isviciidae (upper triassic), Prosbolidae (upper permian), and the recent Cercopidae, we see a certain venational configuration which is not only persistent throughout the Permian and the Triassic up to the present time, but is also preserved when the wings change type, i.e. we see that same venational configuration to be present in them whether the wings happen to be of the neuropterygian type (Archescytinidae), of the elytropterygian type (Scytinopteridae, Cercopidae), or of the heteropterygian type, and which configuration can be depicted as follows :

Figure 20bb :  Persistent and characteristic venational configuration as we see it in the tegmina of the lower permian Archescytinidae, of the upper Permian (and upper Triassic) Scytinopteridae, of the upper permian Prosbolidae, (to a lesser extent in the tegmina) of the upper Triassic Ipsviciidae, and in the tegmina of the recent Cercopidae (all these families belonging to the Order Homoptera). This characteristic and constant venational configuration consists of : (1) a broad costal field, (2) a long radial cell, (3) a long medial cell, (4) the basal section of CuA [= Cu1] up-arching towards the origin of the free Media and either touching it and then leaving it again, or coalescing with it for a short distance, or being connected with it by a short cross-vein, or merely getting close to it for a 'moment', and (5) finally the presence of a characteristic clavus (anal area), distinctly separated from the rest of the tegmen by a straight concave vein, CuP [= Cu2].

Indeed, we see this venational configuration to be present in the forewings (tegmina) of the upper permian  Scytinopteridae :

Figure 20c :  Scytinoptera  obliquo-ovata Mart.,  Scytinopteridae, Order Homoptera. Upper Permian of the Archangelsk Region, Sojana river, Letopala, Russia.  Tegmen. Length 8.9 mm, width 3.9 mm. (After BECKER-MIGDISOVA, 1948)

Figure 20cc :  Scytinoptera  reducta Mart.,  Scytinopteridae, Order Homoptera. Tegmina. Length about 7 mm. Upper Permian of the Archangelsk Region, Sojana river, Russia.  Left :  locality Sheimo-Gora.  Right :  locality Letopala. (After BECKER-MIGDISOVA, 1948)

Figure 20ccc :
16 :  Tegmen of  Actinoscytina  belmontensis Till.  Scytinopteridae. Order Homoptera. Upper Permian of Belmont, New South Wales, Australia. Length 7 mm. Greatest breadth 2.4 mm.
17 :  Tegmen of  Permoscarta  trivenulata Till.  Scytinopteridae. Order Homoptera. Upper Permian of Warner's Bay. New South Wales, Australia. Length 6 mm. Greatest breadth 2.1 mm.
(After TILLYARD, 1926)

. . . in (some) recent  Cercopidae (Cercopoidea, frog-hoppers, cuckoo-spit insects) :

Figure 20d :  Tegmen of  Lepyroniella  petrovi Gregor.,  Cercopidae, Order Homoptera. Recent, Abchasia (Western Caucasus [southern slope] ).  This species has lost its hindwings, i.e. all what is left of them is a membranous rudiment of negligible size. It is known that the venation of the tegmina in this species varies greatly. However, the general venational plan remains intact in most individuals.

We also encounter it in the tegmina of all representatives of the upper permian family Prosbolidae, which we do not hold to belong to the present wing-type [elytropterygia] but to heteropterygia (next four Figures) :

Figure 20dd :  Prosbole  hirsuta Koken.  Family Prosbolidae. Order Homoptera. Tegmen (hemelytron). Length about 4.6 cm. Upper Permian, Kama River, Russia.  (After HANDLIRSCH, in TILLYARD, 1921)

Figure 20e :  Permocicada  idelensis M. Zal.  Family Prosbolidae, Order Homoptera. Tegmen (forewing). Upper Permian of the Archangelsk Region, Sojana river, Iva-Gora, Russia.  Length of tegmen of species 9.45-12.0 mm. (After BECKER-MIGDISOVA, 1940)

Figure 20f :  Tegmen of  Sojanoneura  marginata Mart.  Family Prosbolidae, Order Homoptera. Upper Permian of Tichije Gori, Ural, Russia.  Length of tegmen 15 mm. Clavus not preserved.  (After MARTYNOV, 1931)

Figure 20ff :  Fossil of tegmen of  Sojanoneura  marginata Mart.  Family Prosbolidae, Order Homoptera. Upper Permian of  Tichije Gori, Ural, Russia.  Maximal length of tegmen 12.5 mm. Other specimen [than that of Figure 20f].  (After MARTYNOV, 1931)

. . . and we meet this venational configuration again in all the lower permian Archescytinidae (wing-type :  neuropterygia) :

Figure 20g :  Tegmen of  Permopsylla  permiana Carp.  Family Archescytinidae, Order Homoptera. Lower Permian of Kansas (USA).  Length of tegmen 4 mm, width 1.8 mm. (After CARPENTER, 1931)

Figure 20h :  Permoscytina  kansasensis Carp.  Family Archescytinidae, Order Homoptera. Lower Permian of Kansas (USA).  Drawing of fore- and hindwing. Specimen No. 3881ab.  Length of tegmen of species 11-12 mm, width 3.5 mm. (After CARPENTER, 1938)

. . . and also in the upper permian archescytinid  Cicadopsylla :

Figure 20i :  Tegmen (without clavus) of  Cicadopsylla  permiana Mart.  The missing clavus and basal costal field is shown dotted in. Family Archescytinidae, Order Homoptera. Upper Permian of  Tichije-Gory, Ural, Russia. Total length 13.5 mm. Breadth 6.2 mm.
(After MARTYNOV, 1931)

. . . and again in mesozoic Scytinopteridae :

Figure 20j :  Tegmen of  Mesoscytina  australis Till.  The missing clavus is shown dotted in. Family Scytinopteridae, Order Homoptera. Upper Triassic, Ipswich, Queensland, Australia. Total length 9.4 mm. Breadth at apical end of clavus 3.5 mm.
(After TILLYARD, 1919)

As has been said, with respect to (functional) wing-type, the Archescytindae belong to  neuropterygia,  the Scytinopteridae and Cercopidae to  elytropterygia  (present type), while the Prosbolidae do, as to their wings, belong to  heteropterygia,  whereas taxonomically they all belong to the insect Order Homoptera.

Theoretical evaluation of the above presented persistency of a particular venational configuration in insects. Extension of the noëtic theory of evolution.
In our theory of the Implicate and Explicate Orders of Reality (i.e., respectively, the noëtic and material Orders) we assume, as has been pointed out earlier, that most original immaterial forms (immaterial patterns), present in the Implicate Order as noëtic descriptions, cannot acquire ontological completeness (= becoming ontologically carried by Prime Matter), because they cannot materially exist in the Explicate Order (i.e. material existential conditions for such forms do not and cannot exist in that Order). Some of them, however, but not all, may acquire this completeness by noëtically developing into strategies, i.e. by becoming noëtic descriptions of strategies-to-exist-and-persist-in-the-Explicate-Order. And then, after projection, from the Implicate Order into the Explicate Order, they appear in the latter Order as organismic species, consisting of material, local, and temporal individuals. The subsequent and successive appearance of these species, depending on the presence of appropriate ecological niches (material existential conditions) in the Explicate Order, is then what we call "evolution". It is further assumed that the original immaterial form 'tries' to maintain its identity during its development into a strategy. And in the morphology of the representatives of the corresponding material organismic species this identity remains visible in the set of retained non-functional characters (the functional characters, on the other hand, are the true elements of the strategy precisely as strategy). These non-functional characters may, however, in some cases, be 'overwritten' (i.e. suppressed) by adventive functional elements. And in winged insects it is precisely the venational pattern -- i.e. not the wings as wings, because they are functional structures, but their venational pattern -- which is least sensitve of being so overwritten. It may be partly overwritten though, such as in cases of strong costalization, or the development of an anal fan in the hindwing, but enough of it remains original and thus reflecting the original immaterial form or part of it. So it is often there, i.e. in the venational pattern, where we can find the expression, or part of it, of the identity of the original immaterial form, which, in the Implicate Order was developed into a strategy, giving rise, after projection, of the corresponding organismic species (see for this also the theoretical accounts in  Part II ).
In the context of this theory we will now try to explain the above case (treated just as an example) of persistency of the venational configuration as depicted above in  Figure 20bb  and as we find it in many Homoptera.
As to the original immaterial forms present in the Implicate Order, we do, first of all, not assume that  all  possible immaterial forms, i.e. the complete totality of all the forms that do not contain an internal contradiction, do, 'from the outset', noëtically exist in the Implicate Order. There must be restrictions in that Order as to what immaterial forms (patterns) may exist and what forms cannot exist there. In an earlier version of our theory (in Fifth Part of Website) this restriction consisted in the assumed fact that forms and strategies are being formally derived from one another in the Implicate Order according to certain derivational rules inherent in that Order, that is, monophyletic development was assumed, but a monophyly in that Order only. However, in a later version of our theory -- the reader should understand that the noëtic theory of evolution is gradually being developed, amended, and changed, during the succession of one document after another of this Website (Fifth and Sixth Part), but he or she should also understand that earlier versions keep their intrinsic value, despite later changes, because our theory was not established once and for all from the very outset, and will remain hypothetical, i.e. all of it remains stuff to think about -- we have entertained the possibility that organic evolution is also polyphyletic in the Implicate Order. There, according to this assumption, we 'see' parallel lines, every one of them starting with some given original immaterial form or pattern that, while developing, ends up to become a true "strategy", still, it is true, as an immaterial form existing in the Implicate Order, but then, upon projection, appearing in the Explicate Order as an organismic species. But this assumption, i.e. that of an all-out polyphyly in the Implicate Order, may imply that  all  non-contradictory immaterial forms or patterns or at least those that are not ruled out by the Implicate Order's  general  restrictions other than non-contradiction, do already exist in the Implicate Order from the outset, of which some may develop into strategies, meaning that 'eventually' also  all  possible strategies whatsoever do exist in the Implicate Order waiting to be projected into the Explicate Order. And indeed precisely those strategies of which there exist corresponding ecological niches in the Explicate Order are being projected into that Order. Such a conception is, in a way, similar to the current evolutionary theory which assumes organic evolutionary development of all possible ecological and morphological types to take place as a result of a succession of random genetic mutations, and natural selection of those that improve survival and increases reproduction. Here the reservoir of all possible types, all possible strategies, is in the very randomness of genetic mutations, and so also in this (current) theory everything is, in principle, already present. In our noëtic theory of evolution we want to do away with such a complete reservoir of strategies, i.e. simply transposing things (such as the creation of strategies) from material reality to something like an implicate order is not enough to rationalize evolution, or at least to rationalize the organic world as we find it existing. Also in this Order there must exist restrictions as to what forms can and what forms cannot exist there. Indeed it is restriction, whether by laws or rules, that creates true patterns, especially functional patterns such as strategies. So let us theorize about the nature of such restrictions in even the Implicate Order, i.e. the domain of immaterial and timeless forms or patterns.
In analogy with states of affairs in the Explicate Order, i.e. in analogy with existing restrictions of pattern-formation in the material Order, we are forced to consider that not all logically consistent immaterial forms whatsoever can exist in the Implicate Order. Indeed, in the Implicate Order we must have to do with some analogue of thermodynamic stability and instability of material patterns as we know it to be the case in the Explicate Order. In the latter Order inorganic patterns can only exist and persist, and thus be stable, when they are at thermodynamic equilibrium. So, for instance, crystals. An organism, on the other hand, can only exist and perform its functions, and thus be stable, when it is kept far away from thermodynamic equilibrium. For it thermodynamic equilibrium means instability, death and decay. Let us call the analogy of material stability and instability as it is assumed to be present in the Implicate Order  "noëtic stability"  and  "(noëtic) instability".  In fact, in material organisms (in contrast to, say, crystals) we may, to their thermodynamic stability or instability, add their ecological stability or instability coming over and above the thermodynamics (as the most basic to them). And perhaps the noëtic stability or instability in the Implicate Order is still mirrored precisely as ecological stability or instability (of a species as a whole) in the Explicate Order  ( The stability or instability of a particular here-and-now individual, pointed to, or of a group of such individuals, of a given organismic species is entirely a matter of local conditions in the Explicate Order). So in the Implicate Order we may expect some immaterial forms or patterns that are such that their stability is an analogue of the ecological stability of the corresponding organismic species in the Explicate Order. This means that we must assume an analogue of ecological relationships to be present in the Implicate Order. And these must have something to do with the development of original immaterial forms or patterns into strategies making them able to exist in the Explicate Order and so to acquire ontological completion. So the 'aspiration' of these original immaterial forms to attain ontological completion consists, first of all, in the transition of them into more and more noëtically stable forms, where "stable" here means "approaching to be, or having become a strategy". Such a strategy is, in the Implicate Order, formed by a step-by-step noëtic process, starting with some given originally existent immaterial form, the qualitative content of which we imagine to be a noëtic description (i.e. a description of what it precisely is), and proceeding along lines of increasing noëtic stability, until maximal stability has been achieved, i.e. until a description of a true strategy has been worked out. And, of course, only after projection of this strategy, of this noëtic description, into the Explicate Order, the original form attains ontological completion, because only then it exists, not as a mere description anymore, i.e. not as an immaterial pattern anymore, but in the form of material and temporal individuals of a particular organismic species now materially embodying the strategy. And as such, individuals of this species form an integral part of a true biocoenosis existing at some place and some time, while other individuals of this same species are in the same way connected with another instance of this same type of biocoenosis, or, in other words, the species is embedded in its proper ecological niche, guaranteeing its existence.
It must be emphasized that according to our present (version of) noëtic theory of evolution strategies/species do not evolve from one another, neither in the Explicate Order nor in the Implicate Order. With respect to the former Order this accords well with taxonomic and phylogenetic practise and experience, where it is well known that species and higher taxa resist to be derivable from each other (i.e. the derivation of one given taxon from direct or remote ancestors of the other taxon). Almost all phylogenetic taxa in proposed genealogic trees are admittedly hypothetically connected with one another (by dotted lines). Also in the Implicate Order we now assume that the development of original forms into strategies (in that Order corresponding to organismic species in the Explicate Order) proceeds polyphyletically, every original form developing its own strategy which is the stable endpoint of this (timeless) development. The noëtic stability of forms or patterns in the Implicate Order resembling ecological stability of organismic species in the Explicate Order emphasizes the fact of the close connection between the Implicate and Explicate Orders. This connection mainly consists of the Implicate Order being geared to the Explicate Order, as a result of the 'aspiration' of its immaterial forms to attain ontological completion. So in our theory we let adaptations in organisms (as elements of strategy) be formed in the Implicate Order. Indeed, we do not think the conditions and factors present in the Explicate Order to be capable of generating such adaptations, because there individual, local, and temporal influences occur throughout, messing up particular developments. Not so in the Implicate Order. This Order is time- and spaceless. Forms and patterns are not spatially or temporally separated from each other. There are no individual contingencies messing up development. Forms and patterns exist in the Implicate Order as descriptions as to what they qualitatively are. And when a number of them cannot as such materially exist in the Explicate Order they develop into descriptions of strategies in which they themselves tell how to exist and persist in the latter Order. And, as has been said, in the course of this development the original immaterial forms do not lose their identity, i.e. their identity, although having become more or less concealed by adventitious elements of strategy, is still preserved. And in the corresponding organismic species in the Explicate Order we see this original identity in the form of a set of non-functional species-constant characters. And several different species may possess a part of these characters in common, which does, however not point to common descent, but to similarities present among the corresponding original immaterial forms in the Implicate Order. So in order to identify in the given organismic species the original immaterial form that has been transformed, through increasing noëtic stabilization, into a strategy, and also to identify common features possessed by different such initial immaterial forms, we must distinguish between functional and non-functional characters as present in the given organismic species as they appear to us in the Explicate Order. And although many non-functional characters have been suppressed by functional, i.e. adaptational characters, a number of them have been preserved, especially in the venational pattern of the wings of insects. Thereby we must take account of the fact that wings themselves, as a whole, are functional organs and as such being part of the strategy of a given species of winged insect. And also parts of the original venational pattern may be suppressed by functional features such as costalization or the expansion of the anal area of the hindwings. In fact the wing-types we are considering in the present series of documents are  functional  types, especially the types  orthopterygia,  elytropterygia (present type),  heteropterygiaplatypterygiaptilopterygia,  and  dipterygia.  Nevertheless, except in ptilopterygia (feather-wingedness), many features of the original venation, expressing the identity of the original immaterial form are preserved. This is because persistence of non-functional features in the venational pattern is not expected to interfere with functional features of the rest of the wing or of the rest of the body for that matter. But, some such non-functional features may, precisely because they are non-functional, be influenced and changed by individual and contingent factors acting in the Explicate Order :  Whereas functional characters are expected to be largely resistant to such random factors, non-functional characters are expected to be vulnerable to them. And indeed, this is expressed in the well-known individual variation (apart from sexual dimorphisms and cast-related characters) in the morphology of the representatives of the same given organismic species (even, sometimes, in insects the right and left wing of the same wing-pair might be slightly different). Nevertheless, in many cases, the original venational pattern shines through. But in other cases it may be ruined more or less completely, and this, as things are in individual variation, not in a species-constant manner, resulting in the presence of various stages of destruction of the original venational pattern in individuals of the same species. This is especially to be expected when the venation has  completely  lost all its functional features, even those that would otherwise guarantee the stiffening of the forewings already serving as shielding organs (i.e. the additional stiffening by veins of in themselves still light and soft shields). Indeed, when the stiffening of the wing-membrane has become maximal, the forewings have turned into true strong shields in no need of stiffening veins anymore. So in such cases the venational pattern is completely functionless. This process is carried to its extreem in recent and most fossil beetles (Coleoptera, shield-winged insects) in which the forewings have been transformed into tough elytra and in which the original venation has been completely lost.
Well, in the homopterous recent family Cercopidae we have also to do with tough tegmina (see Figure 17 ),  in which, however, a venation is still present, albeit weakly so (as is also the case in their permian relatives the Scytinopteridae). But because they have functional hindwings the whole flying apparatus is still a functional structure, that is, the forewings, although hardened, do [as far as I know] still participate in flight-movements, meaning that the venation at least partly remains subordinated to flight-functional demands.
But there exists at least one species of Cercopidae, namely  Lepyroniella  petrovi Gregor., in which the forewings are, like in all Cercopids, tough shields, protecting the insect, but in which the hindwings are absent, meaning that the sole function of the forewings is shielding the insect body. So here there is in fact no need of any veins or of any definite venational pattern.  ( Although the shielding-function is also very expressed in all representatives of the Order Coleoptera (beetles), in most of them there exist functional hindwings). Indeed, here (in the mentioned cercopid) we find an extremely great individual variation, such that it is not possible to uncover the original venational pattern of the very  species.  But we may investigate what remains in this species of the more general features of this original venational pattern, which [original venational pattern] we may expect to be more or less similar to the venation as we see it in the permian Scytinopteridae. Indeed we saw above that the tegmina of the permian and triassic family Scytinopteridae, the permian Archescytinidae, some recent Cercopidae, and the permian Prosbolidae all have some particular venational configuration in common. The reader may inspect the above Figures starting with  Figure 20bb.
We will now describe (following BECKER-MIGDISOVA, 1948) the above mentioned cercopid in which the venation of the tegmina has lost all functionality, and see the resulting individual variation of it.
Lepyroniella  petrovi Gregor. (Cercopidae, Homoptera, recent) inhabits the beech forests of Abchasia (western Kaukasus, southern slope) exclusively in clearings of mountain slopes, covered with growths of rhubarb and fern. They are almost never encountered in grassy clearings where their presence was connected with the presence of the growth of those same plants. In the valleys they are not encountered at all.  L. petrovi represents an insect that has lost its hindwings, which have become, as to their size, an insignificant membranous rudiment. The tegmen also has lost its original flight-function, being a shielding organ having been transformed into a heavily sclerotized evenly thickened chitinous scale. In connection with this, the wing-venation has lost its significance as skeleton serving to support the membrane of the wing. The venation became "indifferent", the veins weak. Because the venation of the tegmen already has no functional significance whatsoever, its change is not consolidated by selection and does not become constant and fixed. Indeed, we have to do here with an unusual amplitude of variability of the venation of the tegmina (see next series of Figures). We must add that in strong variability of size, sexual dimorphism is sharply expressed whereby the tegmina of the males are smaller. In coloration, apparently, there is no sharply expressed sexual dimorphism. Both sexes possess tegmina from unicolored white up to a covering of dense grey-brown marking, whereas in the females, apparently, we do not meet with too much of a dark grey-brown color. With the coloration of the tegmina the color of the body from whitish to grey-brown is also connected and sometimes with a dark grey-brown abdomen.
Let us now figure the tegmina of this one species Lepyroniella  petrovi Gregor., showing their variability in coloration and venation. All Figures are taken from BECKER-MIGDISOVA, 1948. We compare these tegmina with our Figure 20bb which depicts the typical venational configuration. The peculiar course of the anal veins (Y-vein) in the clavus in this Figure is not considered typical.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  is present, although there is no connection between CuA and M.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  is present. CuA coalesced for some distance with M. Basal piece of CuA absent.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  is present. CuA touching M. Basal piece of CuA present.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  is present. CuA connected with M by a short cross-vein.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  is destroyed as a result of the reduction of M (only a trace of it is left).

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  only partially intact. Clavus absent.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  is present. CuA coalesced with M for a considerable distance. Basal piece of CuA still present.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  is largely intact.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  is largely absent.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  is present. CuA not connected with M.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  rudimentary.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  rudimentary.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  rudimentary.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  rudimentary.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  rudimentary.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  rudimentary.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  rudimentary.

Lepyroniella  petrovi,  Family Cercopidae. Order Homoptera.
The venational structure highlighted in  Figure 20bb  present. CuA not connected with M.

What we see in these tegmina of Lepyroniella  petrovi Gregor is that the venational structure highlighted in  Figure 20bb  is, despite great venational variation in this species, still present, or at least largely so, in almost all these tegmina. It proves to be a persistent feature, resisting the action of contingent (environmental) factors in the Explicate Order. And this persistent feature expresses part of the qualitative content of the original immaterial form that has, while keeping up its identity, developed into the particular strategy, in the Explicate Order represented by the species Lepyroniella  petrovi. But this persistent feature is not only the material expression of a part of the mentioned original immaterial form, but is commonly possessed by a large number of other original immaterial forms as well, as is evident in the wide distribution of the venational structure (Figure 20bb) among insects of the Order Homoptera.
Phenomena like this abound in organisms of all sorts, and in the wing-venation of insects it is especially evident.
Let us theorize all this a bit further.
In the present version of our noëtic theory of evolution (developed from the later documents of  Fifth Part of Website onwards) we assume an all-out polyphyletic development of organisms, in the sense of the independent origin of species (i.e. species did not evolve from each other), not only so in the Explicate Order (where they  appear (on the scene) independently of one another as to their very essence (but not as to their ecology)), but also (do they develop polyphyletically) in the Implicate Order (strategies have not evolved from each other), meaning that each (still immaterial) strategy has developed from a single original immaterial form which itself was not a strategy at all. How this can happen, -- i.e. how precisely a strategy may noëtically develop from a more or less indifferent original immaterial form, a strategy which, when materially represented in the Explicate Order, is often so subtle and crafty, -- truly is a great mystery. We have already pointed out that current evolutionary theory cannot account for the origin and existence of the many strategies-to-exist embodied in living organisms. Neither in fact can we, -- but we hope that our alternative of the current theory, our noëtic theory of evolution, may eventually develop into a more plausible account of the origin and existence of these strategies.
Because all immaterial forms do possess an immanent tendency to become material, i.e. to become ontologically complete, the Implicate Order (which is the very domain of immaterial forms and patterns) is naturally geared to the Explicate Order (which is the very domain of material forms and patterns). And because  being material  is the same as  existing in the Explicate Orderexistential conditions  of organismic species, as we see these conditions to exist in the Explicate Order, must, in a noëtic fashion, also exist in the Implicate Order  ( This is the Implicate Order's way of being geared to the Explicate Order).  And a given  original immaterial form, -- which happens to be of such a nature that it cannot (already) as such, i.e. not without first having been transformed qualitatively (not ontologically),  materially exist in the Explicate Order, -- iswhen not yet having developed into a strategy (which makes it able to so exist),  precisely of such a nature that its course (of transformation) (leading it) to noëtic stability necessarily leads it at the same time to a particular noëtically represented existential condition (in the Implicate Order), and its  noëtic reaction  with it then results in a particular strategy (still immaterially represented), which, after projection materially appears in the Explicate Order as a particular organismic species. So it is a  noëtic reaction  (i.e. a reaction between immaterial forms or patterns) that is responsible for the origin of strategies, and not a material reaction as is assumed by current evolutionary theory. To sum up, the noëtic reaction of a given existing original immaterial form with a particular noëtically represented existential condition results in this immaterial form to be transformed into a particular strategy without losing, however, its original identity. The latter can still be recognized in the set of non-functional characters having been preserved in the morphology of the individuals of the corresponding organismic species.

Summary of present extension of noëtic theory of evolution so far developed
Reality (i.e. that which exists in one way or another) is assumed to contain two interconnected ontological (i.e. as to the way of being) domains, viz., the material Explicate (unfolded along time and space) Order and the immaterial Implicate (enfolded) Order. While the entities present in the former Order do exist there materially (implying physical individuals, contingency, place and time), the entities of the latter Order are entirely immaterial (excluding individuals, contingency, place and time).
Material and immaterial forms differ from each other not necessarily as to their qualitative content, but as to their ontological composition (which determines their way of being). A form to be  immaterial  means that the ontological substrate, prime matter, is absent in it, meaning that its qualitative content is not ontologically carried by anything. A form to be  material, on the other hand, means that its qualitative content (its form proper) is carried by prime matter, its ontological substrate. Prime matter only has a substrate function, it has no qualitative content whatsoever. Therefore, the addition of prime matter to an immaterial form does not add or subtract anything to or from the form's qualitative content. It only makes possible the existence of various physical here-and-now individuals all possessing precisely the same qualitative content, i.e. it makes possible the repetition of a same given form (a same given qualitative content) in place and time, and therewith introducing possible contingencies. This is true Greek philosophy (that of Aristotle), but in contrast to it we hold the  material  form, i.e. the materialized form, to be the most perfect way of being (while the Greeks attributed this to the immaterial pure form). And materialized forms do only exist in the Explicate Order. Or, in other words, existing in the Explicate Order is existing in the most complete way, because it is  materially  existing. When a given immaterial form is projected from the Implicate Order into the Explicate Order it is unfolded along the space and time dimensions of that Order. In organisms this means that a given immaterial strategy (a description) appears in the Explicate Order as a multitude of here-and-now individuals of a particular organismic species. In our theory we equate the  immaterial condition  of a given qualitative content with  a  description  of that content.  Being a description = being immaterial (i.e. without prime matter). Not a description made by someone or something, but just a description.
Because all immaterial forms or patterns intrinsically aspire after their ontological completion by becoming material, i.e. by coming to exist in the Explicate Order,  the Implicate Order is as to its very nature ontologically geared to the Explicate Order, geared, that is, to express its forms materially, and, as a result of this, contains noëtically represented (i.e. in the form of a description) non-contingent existential conditions for these forms to exist materially in the Explicate Order.
Every immaterial form whatsoever, present in the Implicate Order, which cannot materially exist without having first undergone appropriate transformation, which (form) is, in other words, unstable,  is,  as to its very qualitative identity (i.e. as to what it is), such, that its subsequent course to noëtic stability leads it to a particular noëtically represented non-contingent existential condition (and, with respect to this given particular form, only to this particular condition), i.e. makes it reactive with that condition. The product, emerging from this noëtic reaction between (1) particular immaterial form and (2) corresponding noëtically-represented existential condition, is a particular strategy (describing how to exist in the Explicate Order). And only now the original immaterial form has achieved stability. This strategy is then in the Explicate Order expressed as a material organismic species provided with a set of special adaptations to the material counterpart of the noëtically-represented existential condition, i.e. (expressed) as an organismic species fully integrated in its proper environment. And so, every organismic species represents its own specific strategy, a strategy to exist in its own environment (in the most narrow sense). In the morphology of the individuals of such a species the qualitative content or identity of the corresponding original immaterial form may be seen materially expressed in the species's non-functional characters. The succession of appearance of organismic species and types one after the other in geologic time in the Explicate Order is experienced by us (in fact theorized by current evolutionary science) as a transformation of existing species into other species as a result of either the migration of the former into new environments, or the long-term influence on existing species of a changed environment.

* * *

4.    Eu-elytropterygia
Most progressive is, as the probable derivative of  blattopterygia, the chief subtype of shield-wingedness, expressed in the Order Coleoptera (beetles), eu-elytropterygia, of which extreme stiffening of the forewings with a strongly changed venation, is characteristic [see Figures 1-10 ,  especially Figure 4 ].  The hindwings, see Figure 10, acquire well-expressed traits of aerodynamic specialization -- they become pointed, strongly costalized, often recalling us, as to their structure, cases of extreme costalization in the type of twofold-wingedness (dipterygia). This correspondency sometimes ends up with extreme similarity. See next Figure.

Figure 21 :  Wing of  Plegaderus  vulneratus Panz., Histeridae, Order Coleoptera. Europe.

Among the diverse examples of eu-elytropterygia we may mention the existing further courses of differentiation of this type, consisting in the loss, for the forewings, of the necessity to lift, and setting free in this way the hindwings hidden underneath them (some Scarabaeidae -- Cetoniini and Scarabaeini, the genus Gymnopleurus), or [consisting] in the reduction of the size of the forewings, the elytra, as in the Staphylinidae (rove beetles),

Figure 22 :  Xantholinus  tricolor, Staphylinidae, Order Coleoptera. 7.5-11 mm.
(After SEVERA, in Thieme's insektengids voor West- en Midden-Europa, 1977)

. . . or, finally, in the loss of the necessity of folding the hindwings (a whole series of families of beetles, some Meloidae, Rhipiphoridae, Lymexylidae, Petriidae, and others). All these transformations of eu-elytropterygia, undoubtedly point to the working-out of [at least] traits of the most perfect type -- dipterygia, most perfect functionally (flight by  a  s i n g l e  pair of wings), as also with respect to morphological similarity (the structure of the costalized hindwings).
In addition to these undoubtedly progressive, with respect to flight, changes in eu-elytropterygia, there has taken place the working-out of a passive form of specialization of the flying-wings of the most minute beetles, leading them to the type  feather-wingedness :

Figure 23 :  Wings of  feather-winged beetles.  Left - Nossidium sp.  Right - Ptilium sp.
(After STURM, in ROHDENDORF, 1949)

5.    Metelytropterygia
Another kind of extreme form of shield-wingedness is illustrated by the order Dermaptera, earwigs, -- ultra-shield-wingedness, i.e. metelytropterygia (met-elytro-pterygia). Of this subtype shortening of the elytra down to a small size, to almost quadratic blades -- caps, holding the multiple-folded along longitudinal and many transverse folds in the form of a small compact packet very broad fan-shaped hindwings, is characteristic. See next Figure.

Figure 24 :  Left hindwing of the earwig Forficula  auricularia L., Forficulidae, Order Dermaptera.  The wing is spread out, and the sclerotized structures have been kept dark. Folds are drawn as dashed lines. The wing-blade is divided into convex (kx) and concave (kv) radial folds, that are pushed fan-like together when the wing is folded. The in this way formed compact fan is then further, along the ring-fold RF, running perpendicular to the radial folds, turned up with the distal part. Where the ring-fold crosses the drawn-black Radial veins (Rad) and the intercalary veins (lc), the veins look "damaged" (indicated by punctuation). At the level of the wing-medium-joint (FMG) a further folding turns the wing down against the ulnar field (UF), and thus the twice-folded wing-packet is brought under the stiff elytron (Sq).
An - first Anal vein.  ap1 + ap2 - external and internal apical field.  Ax 2 - second axillary sclerite.  K. Lf - concave longitudinal fold in the ulnar field (in flight it serves as some sort of flight-fuse. There is yet a second fuse).  Lig - wing-ligament.  Mf - marginal field.  V.sp. - Vena spura.  Zw. - intermediate field. (After NACHTIGALL, 1968)

Figure 25 :  Forficula  auricularia, Forficulidae, Order Dermaptera.  Elytron from above, with translucent tracheae.
(After MARTYNOV, 1938)

Figure 26 :  Forficula  auricularia, Forficulidae, Order Dermaptera. 14-23 mm.
(After SEVERA, in Thieme's insektengids voor West- en Midden-Europa, 1977)

The origin of metelytropterygia of the earwigs is not clear. Perhaps it is a further stage of the protelytropterygia of the permian Protelytroptera (see Figure 16 ).
Interrelationships and connections of elytropterygia are drawn in the next diagram.

Figure 27 :  Interrelationships with other types and structure of shield-wingedness (elytropterygia).
I - neuropterygia.
II - blattopterygia.
IV - orthopterygia.
VII - heteropterygia.
VIII - strepsipterygia.
XII - ptilopterygia.
Arabic numerals signify corresponding subtypes (i.e. subtypes of the present type).
(After ROHDENDORF, 1949)

This concludes the exposition of shield-wingedness. The next document will deal with straight-wingedness (orthopterygia).

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