DESCRIPTION OF PLATE E. 



Reproductive Organs of the Oviparous Aphis. 



Fig. 1. — Reproductive organs contained within the 

 last four segments of the body of Oallvpterus quercus : 

 a, left half of the oviduct, the elastic walls of which 

 are composed of numerous circular transverse muscular 

 fibres. The internal longitudinal fibres are not here 

 seen. Shortly after the union with the right half of 

 the oviduct a short vaginal tube is continued down- 

 wards. This last ends in a wide-mouthed vulva, the 

 entrance to which, and walls also of the vagina, are 

 effectively controlled by fasciculi of muscles ; three 

 on either side, so disposed that by their contractions 

 the vagina and its entrance can be reduced to a narrow 

 slit, and thus closed, e e, colleterial glands which end 

 in attenuated ducts. These — the muciparous glands 

 of other authors, anastomose into the walls of the 

 vagina, into which passage they pour their lubricating 

 secretion. The glands are large, very tough, and 

 easy to be seen. Above these, but less obvious, is d, 

 the spermatheca or pouch for storing the spermatozoa 

 or male cells. 



Balbiani says that the intromittent organ of the 

 male penetrates into the spermatheca. I could not 

 certainly trace the insertion of the duct into the 

 vaginal walls, but Morrens, Huxley, and Balbiani 

 locate it above the insertion of the colleterial glands. 



Besides these organs, I have been able to note that 

 the large trumpet-mouthed nectaries in this species 



