158 MOLLUSC A 



4. The spermatophoric organ lies almost on the left side, 

 but a little ventrally. In it the spermatophores are formed. 

 It consists of a series of glands and mechanical arrangements 

 that secrete and wind materials into spermatophores. It con- 

 sists of a number of parts. 



(a) On the right dorsal side, the part joined by the vas 

 deferens, is the mucilaginous gland. This consists of two 

 parts. 



(b) The ejaculatory apparatus gland extends from the 

 mucilaginous gland posteriorly and then ventrally. Both ends 

 of this gland are marked by constrictions. 



(c) From this gland forward to a narrow duct is the 

 middle tunic gland. 



(d) The narrow duct leads into a large blind pouch and is 

 the outer tunic gland. 



(e) The large blind pouch extends posteriorly nearly the 

 length of the organ and is the hardening gland. 



(/) A branch leaves the narrow duct just before it enters 

 the hardening gland that leads to the curved anterior extrem- 

 ity of the gland. This is the finishing duct. 



(g) The finishing duct leads to the curved gland men- 

 tioned, the finishing gland. 



This completes the spermatophoric organ, although some 

 minor structures have not been mentioned. A section across 

 the ejaculatory apparatus gland will show a large ridge with 

 a groove along one side through which the spermatophore 

 travels and rotates while being formed. 



5. From the last part of the spermatophoric organ, the 

 finishing gland, a straight duct leads posteriorly by the side of 

 the vas deferens to join the spermatophoric sac about the 

 length of a spermatophore from its posterior end. This is 

 the spermatophoric duct. 



6. The spermatophoric sac is somewhat spindle shaped, 

 usually filled with spermatophores, and joins the base of the 

 penis. 



Make a drawing of the system. 



