156 Miscellaneous. 



At the same time I have carefully examined various other 

 Aphides of the group of true Aphidinae with long 7-jointed an- 

 tennae. The following is what I have observed : — 



The false female, or foundress pseudogyne, which issues from the 

 egg in the spring, always remains apterous. In from twenty to 

 thirty days it produces living young, most of which continue apte- 

 rous, while some acquire wings. These two forms, which are 

 generally deficient among the Pernphiginae, become fitted to bud in 

 their turn in about the same length of time (about a month), and 

 then all the individuals produced either by the apterous or by the 

 winged forms acquire wings and quit the cradle of the family. 



Where they go I have not yet been able to discover ; but the fact 

 is, that at the end of June all the Aphidinae have disappeared and 

 none or very few of them are to be found on the trees and bushes. 



Although I have been unable to trace this emigrant pseudogyne, 

 which leaves a regrettable gap in the evolution, I have in autumn 

 met with the pupiferous pseudogyne, which, just as in the case of 

 the Pernphiginae, returns to convey the sexual forms to the tree 

 upon which they are to copulate and leave the eggs which will 

 produce the foundress in the ensuing spring. 



The Aphides that I have been able to observe are as follows : — 

 Aphis atriplicis, A. avenue, A. craccivora, A. donacis, A. evonyzni, 

 A.frangulce, A. mali, A. padi, A. persicae, A. pyri, A. viburni, 

 Siphonophora absinihii, RJwpalosiphum persicce, Hyalopterus pruni. 

 Quite unlike the sexual forms of the Pemphiginae, little creatures 

 without either wings or rostrum, the sexual forms of the Aphidinae 

 have a rostrum, and, with rare exceptions (A. mali, S. absinihii), 

 the males are winged, but the females are always apterous and lay 

 several eggs, while among the Pemphiginas and Phylloxerinie the 

 egg is single. 



I should not have made this incomplete communication to the 

 Academy if M. Kessler, of Cassel, who is occupied with the same 

 studies as myself, had not made a communication to the Leopoldino- 

 Caroline Academy upon the same subject *. His observations are 

 identical with mine, and relate in great part to the same insects : — 

 A. padi, A. evonymi, A. viburni, A. mali, A. pyri, A. sambuci. 

 As he does me the honour to adduce these facts as a confirmation 

 of my theory of the biological evolution of the Aphides, I must say, 

 in my turn, how happy I am to see such earnest observers as M. 

 Kessler bringing their aid to the investigation of those terrible 

 enemies of our crops which are known as Aphides. — Comptes 

 Rendus, December 29, 1884, p. 11G3. 



* Nova Acta Acad. Leop.-Carol. Nat. Cur. xlvii. no. 3. 



