THE ANATOMY OF THE ADULT MOSQUITO 



109 



elements, and therefore cannot also as Arribalzaga supposed, 

 secrete the gelatinous fluid that cements together the eggs in 

 the " egg-boats." 



The ducts of the spermothec^e are strengthened by a 

 spiral fibre of chitine, just as in those of the salivary 

 glands ; and just behind their entry into the common 

 oviduct will be seen that of a special accessory gland which 

 secretes a mucilaginous fluid which can hardly have any 

 other function than to furnish a protective coating to the 

 eggs, and to cement them together in those genera which 

 deposit them in boat-shaped masses. 



Fig. 27. —Sagittal Section of last Abdominal Segment of a 9 Culex, 



SHOWING THE EnTEY OF THE SpERMOTHECA AND CeMENT GlAND INTO 



THE Oviduct. (After Kulagnin.) 



The male generative organs consist of a pair of small 

 yellowish bodies, the testicles, from which the sperm is 

 carried by the vasa deferentia, which are simple straight 

 tubes, to the ejaculatory duct which originates in their 

 union. Just before the termination of the vasa deferentia, 

 they receive the ducts of the receptacula seminales. 



The function of these vesicles requires further investi- 

 gation, as their contents do not, as one would expect, 

 consist of spermatozoa floating in a simple fluid, but of 

 spermatic elements in various stages of the process of 

 spermatogenesis, anterior to the appearance of completely 

 developed spermatozoa ; and what is more remarkable, 

 these are not floating in fluid, but are entangled in a fibrous 



