THK SNAIL 



389 



Spermatozoa pass from the hermaphroditic duct into the sperm 

 duct, and enter the vas deferens which terminates in a muscular 

 penis. By means of the latter organ sperm are transferred into the 

 seminal receptacle of another snail. Ova are passed from the ovo- 



Albumin qtand -t^ 



DVer 



hermaphroditic qtand 



Crop 



f^it Oviduct 



r-JI Oart sac 



Wf- MucotAS qlands 



— . bfZ 



Pig. 155. — Genitalia of Helix aspersa; act of union. (Modified, after Cooke, Cam- 

 bridge Natural History. By permission of The Macmillan Company.) 



testis into the hermaphroditic duct, and from there into the oviduct 

 which terminates in a thick-walled muscular • vagina. During this 

 journey the ova are fertilized by sperm from the seminal receptacle 

 and coated with albumin from the albumin glands. Both the penis 

 and vagina have a common genital opening to the exterior. 



