DESCRIPTION OP PLATE G. 



Fig. 5. — A fascicle of testes dissected from the 

 winged male of Lachnus pinicola in October, showing 

 the presence of similar sperm-cysts at u and v. 



Fig. 6. — Highly magnified view of the apex of the 

 penis of the winged male of Dryobius roboris, showing 

 the different folds of the organ when protruded : m, 

 meatus penis ; c, inner fold, as in fig. 2, which by its 

 eversion has become the outer fold. In a similar 

 manner j, as in fig. 2, has become the inner fold of 

 fig. 6 ; d, duct from vesicula seminalis ; p, part of 

 testis which has descended ; s, spermatozoa ; s", the 

 same magnified 206 diameters. Their motion in the 

 liquid was very feeble, and I could detect no filaments. 



Fig. 7. — Part of the male organs of Aphis dirhoda 

 dissected in weak syrup : c, Cauda ; r, armature ; p, 

 hooked penis ; m m, muciparous glands ; a, alimentary 

 tube ; 1 1, testes connected with the vasa deferentia v. 



Fig. 8. — Single branch of testis from the winged 

 male of Aphis opiina : t, t, sperm capsules ; v, seminal 

 vesicle ; m m. muciparous glands. The excretory duct 

 was not visible in this preparation. 



