MANUAL OF ZOOLOGY 



SECT. 



228 



in the thorax, just beneath the floor of the pericardial 

 sinus, and consists of paired anterior lobes (/.) and an 

 unpaired posterior lobe (u.). From each side goes off a 

 convoluted vas deferens (vd.\ which opens on the proximal 

 segment of the last leg. The sperms are curious non- 

 motile bodies produced into a number of stiff processes : 



FIG. i2i. Reproductive organs of Astacus fluviatilis. A, female ; B, male, od. 

 oviduct ; oe, its external opening ; <n>, ovary ; /. testis ; . unpaired posterior 

 portion of gonad ; vd. vas dfiferens. (From Lang's Comparative A natotny, 

 after Huxley.) 



they are aggregated into vermicelli-like spermatophores by 

 a secretion of the vas deferens. 



The ovary (A, ov. u.) is also a three-lobed body, and is 

 similarly situated to the testis : from each side proceeds a 

 thin-walled oviduct (<?^), which passes downwards, without 

 convolutions, to open on the proximal segment of the third 

 or antepenultimate leg. The eggs are of considerable 



