XII 



PHYLUM MOLLUSCA 



723 



Reproductive system. In the male the testis (Fig. <;:*.">. te) 

 forms a compact mass of minute tubules situated in the aboral 



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

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

 cavity of the capsule towards the right; it opens into ;m 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, ofticiiialis, 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- 

 cardium) and the lateral iiephridial sac ; br. lit. branchial heart; inf. funnel ; ink. <. ink-sac : 

 int. intestine; Int. s. lateral nephridial sac; Hi: liver; me<l. s. median iiephridial sac; or. 

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

 appendages ; sh. shell ; st. stomach; <',: ureter; vent, 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 spermatophore (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 spermatophoral sac or Needham's sac (Fig. 635, sp. s) in the 



3 A 2 



