XII 



PHYLUM MOLLUSCA 



723 



Reproductive system. In the male the testis (Fig. 635, te) 

 forms a compact mass of minute tubules situated in the aboral 

 region of the body and enclosed in a capsule. The single kpermi- 

 duct (v. def) is a greatly convoluted tube which leads from the 

 cavity of the capsule towards the right ; it opens into an elon- 

 gated vesicula seminalis (ves.), to which is appended a glandular 

 body, the prostate (pr.). In the interior of the vesicula seminalis 



FIG. 634. Sepia officinal is, diagram of a median vertical section of a female specimen,|to 

 show the relations of the cavities, ap. aperture between the secondary body -cavity (peri- 



Icardium) and the lateral nephridial sac ; br. lit. branchial heart ; inf. funnel ; ink: s. ink-sac ; 

 int. intestine ; hit. s. lateral nephridial sac ; liv. liver ; med. s. median nephridial sac ; or. 

 ovary ; or. ap. aperture leading from oviduct to secondary body-cavity ; pane, pancreatic- 

 appendages ; sh. shell ; st. stomach; v.r. ureter | rent, ventricle. (From Vogt and 'Jung, after 

 Grobben.) 



the sperms are rolled up by the action of a system of grooves and 

 ridges into long narrow bundles of about 2 cm. in length, each 

 of which becomes enclosed by a chitinoid capsule of a narrow 

 cylindrical shape, forming a spermatopliore (Fig. 636, B) ; at one 

 end of the spermatophore is a complicated apparatus of the nature 

 of a spring for causing the rupture of the wall and the discharge 

 of the sperms. The vesicula seminalis expands into a wide sac 

 the spermatoplioral sac or Necdham's sac (Fig. 635, sp. s) in the 



3 A 2 



