No. 443.] 



NOTES AND LITERATURE. 



and digestive and reproductive organs, but his main purpose ana nis 

 best results are in the study of the pupal tracheal system, and in the 

 relation of the same to the venation of the adult wing. Most of his 

 conclusions are abundantly evidenced, though some of them are not 

 entirely new : but one of them at least — his two systems of trachea; 

 and veins, radial u d n lian- ; of very doubtful value : it rests 

 on altogether insufficient evidence. Lepidoptera alone with their 

 single pair of longitudinal trachea; trunks, are too highly specialized 

 to show what was the primitive manner of grouping. In the light of 

 facts presented by other more generalized orders — facts that are set 

 forth in a paper that the author repeatedly cites 1 — such grouping 

 seems little less arbitrary than that of Spuler (into " spreitentheil " 

 and "faltentheil ") which Dr. Enderlein justly condemns. 



He rinds in the end that his aberrant moth represents in the con- 

 figuration of its venation from the ontogenetic point of view a pupal 

 stage preserved in adult life : from the phylogenetic point of view, a 

 one-sided reversion to a phylogenetically earlier stage, that is now 

 normal to no living Saturnian moth. ^ ^ ^ 



Durin^Ae^ the wing is directly evaginated down 



ward underneath the cuticU and is mere!) uncovered by the las 

 moult. His « recessed type " in which the wing rudiment withdraw, 

 slightly from the surface to the bottom of a hypoderma poc e . as 

 Corethra, and his "enclosed type," in which the wing wit raws . 

 is shut in by the closure of the pocket, as in Lepidoptera gene y 



"lie ^tadtttfMl "the wings and spiracles arise in homologom 



