MEMOIES OB' THE >^ATIONAL ACADEMY OF SCIENCES. 



85 



Fig. 47.— Venatiou of fore "wing of Ful- 

 gora.— Alter Spuler. 



Spuler also shows that the venatiou of the Ortlioptera, especially their most generalized form 

 Blatta, is faiulamentally nearly identical with that of the Lepidoptera, veins I-V being readily 

 homologized with those of the latter group; so also with the most gene ralizcd Heuiiptera (Fulgora, 

 fig. 47). We imiy also draw attention to the remarkable resemblance in the venation of the 

 generalized Psocid genus Amphientonium, which at first sight, 

 from the shape and size of the wings, reminds one of a Micro- 

 pteryx or Eriocephala, while it also has a few 

 scales like those of these moths. 



But tbat the system of venation of Spuler 

 is morphologically the correct oute is fully 

 and satisfactorily proved by the ontogenetic 

 development of the veins. Fritz Midler 

 (Kosnios, i, p. 390) was the first to examine 



the incipient venation of two semipnpal moths (Castnia ardalus). He 

 observed that in the immature pupa the cross veins were wanting, and that 

 different longitudinal veins, which afterwards more or less completely disap- 

 peared, were present, and heuce he regarded the pupal venation as the primi- 

 tive one. This view Spuler has adopted 

 and extended, and it plainly enough, 

 supported by the researches of Brauer and Eedtenbacher on 

 the venation of the nymph of Odonata, solves the problem 



of the venation of insects in general 

 and especially for ]S"europtera, Tri- 

 choptera, Mecoptera (Panorpidfc), 

 Lepidoptera, and Di^jtera. 



Spuler's melhcd was to strip off 

 the loose skin of a caterpillar just beginning to pupate, and examine the 

 incipient venation of the wings of the young pupa on the living insect. He 

 placed the living pupa in water and then, since the process of thickening 

 and resulting concealment of the veins of the wing is retarded, the tra- 

 cheal branches become slightly enlarged, filled with air, and thus are more 

 easily seen. Hence 



T 



Fig. 48.— Venati.iu of 

 seluipupa of Cerura li, 

 nula. — After Spuler. 



/ft -Ol J A 



Fio. 40. — Venation of Oracitaria syriji'jella; A 

 motli; B, of aemipupa. — After Spuler. 



Fig. 50. — Venation of Taicepo- 

 ria pbeudoboinbyceUa. — A fter 

 Spuler. 



small pupu' from which 

 the larval skin has just been cast, and are trans- 



parent, are the fittest objects for examination. 



The primitive and generalized condition of 

 the semipnpal wing is shown in Spuler's figure 

 of Centr(( viiiuhi (fig. 48), to which we have 

 added the numbering of all the veins. He shows 

 that the fundamental ])upal venation of Lepi- 

 doptera will also apply to Orthopteia (Blatta), 

 Hemiptera, Trichoptera, etc. He proves that 

 the cross veins are of quite secondary and subor- 

 dinate importance. The results of Spuler's in- 

 vestigations, extended tiirough difierent groui>s 

 from Tineina to Ehopalocera, and illustrated by 

 many figures, are both interesting and convinc- 

 ing. The compari.-^on of the venation of the 

 fore wing of the adult of Gracilarta KyrinijcUa 

 (fig. 49, A), compared with that of its semipupa 

 (fig. 49, B). shows that the generalized venation of the latter is similar to that of Micropteryx, 

 veins IVi IV., not being connected by a cross vein with III and its branches; and veins II and 

 III with their branches, being separate. The veins and tlicir numbering are indicated by Spuler's. 

 figure of Tahvporia pseudulxniihiii-i-Jhi and one we have drawn of HcpiaJus miistelinus (fig. 51 ). 



Fig. 51.— Venatiou of Hepialus muetelimts; d, anterior ; rf'. posterior 

 discal veiu : j. jui:um. 



