PHYLUM MOLLUSCA 



775 



each containing a single ovum at various stages of development, 

 and supported on a long slender stalk. At the breeding season 

 the ovary becomes a compact mass of ova, which assume a 

 polygonal shape owing to mutual pressure. The oviduct (ovid.) 

 is a wide tube, opening, as already described, into the mantle- 

 cavity to the left of the rectum. Occupying a conspicuous 

 position on the anterior wall of the mantle-cavity of the female 

 is a pair of large flattened glands of somewhat oval outline, the 



sp 



B 



Fn ;. r>72. Sepia, reproductive organs of male. pn. penis ; 

 pr. prostate ; p. *. sperm-sac ; te. testis ; v. d<ef. vas 

 defcrens ; res. vesicula seminalis. (After Keferstein.) 



FIG. 673. Sepia. A, sperms, 

 highly magnified ; B, sperma- 

 tophore. p. mass of sperms ; 

 spr. spring apparatus by which 

 the wall of the spermatophore 

 is ruptured. (From Yogt and 

 Jung.) 



nidamental glands (nid\ situated to the 

 right and left of the ink-duct. In the 

 long axis of each is a median canal, on 

 either side of which is a range of closely-set delicate lamellae ; the 

 median canal opens into the mantle-cavity by a slit bounded by a 

 number of plaits situated at the narrower oral end. The nida- 

 mental glands secrete the viscid material by means of which the 

 eggs when deposited adhere together in masses. A glandular 

 mass of unknown function, known as the accessory nidamental 

 glands (ac. nid.), lies at the sides and around the oral ends of the 

 nidamental glands proper. 



