REPRODUCTIVE SYSTEM. 



355 



a large number of spermatozoa, and is transferred by the 

 penis into the genital aperture of another snail. 



(/) Continued from the oviducal side of the common 

 duct, there is a separate ciliated oviduct. This has a short 

 course, and ends in the common genital aperture. Before 

 it reaches this, however, the oviduct is associated with two 

 structures. The first of these is a long process, as long as 

 the common duct, beside which it runs, in appearance 



Fig. 115. 



-Dissection of Helix pomatia. 

 Leuckart. ) 



(Mainly after 



n.r.^ Nerve ring ; s.g.^ salivary glands on the crop ;/., foot ; d.g.^ 

 digestive gland opening into mid gut ; h. heart; k. kidney ; r., rectum ; 

 A', hermaphrodite organ in terminal part of digestive gland ", h.d.^ 

 hermaphrodite duct; a.^. , albumen gland ; c.^., common duct, with 

 more convoluted oviducal part; z<.rf., vas deferens entering penis; 

 jfl., fiagelluni ; r.s. receptaculum seminis, with a branch from its 

 duct ; m.g.f mucus glands ; d.s., dart sac. 



suggesting the flagellum, but expanding at its free end into 

 a globular sac — the receptaculum seminis. It is into this 

 long duct and sac that a spermatophore from another snail 

 passes, and is after some days dissolved, liberating hundreds 

 of spermatozoa. By these spermatozoa the ova of this snail 



