STRUCTURE OF THE EARTHWORM. 



'95 



These vesicles (Fig. 62, s.v.) are very prominent, and seem to 

 be outgrowths of the septa between segments nine to twelve. 

 Among the spermatozoa there are parasitic Gregarines 

 {Afonocystis) in various stages of development. 



(3) The spermatozoa pass from the seminal vesicles into 

 two vasa deferentia or male ducts. These open to the 

 exterior on the 15th segment. Each vas deferens bears 

 two ciliated funnels, which collect spermatozoa in segments 

 10 and II, and soon unite in one duct. 



{b) The Female Oj-gwns consist of two ovaries, and 

 two oviducts each of which has a side receptacle for the 

 eggs. 



(i) The two ovaries are small bodies situated near the 



Fig. 62. — Reproductive organs of Earthworm. 

 • (After Hering.) 



iV., Nerve cord ; T'., anterior testes; Ji"., sacs of setae i ^..S'., recep- 

 tacula seminis ; i-., seminal funnels; 7'.i?., vas deferens, ovd.^ 

 oviduct; t?Z'., ovary; s,v.^ seminal vesicles; F///.-A/'., segments. 



nerve cord on the septum between segments 12-13. Each 

 is pear shaped, the stalk of the pear being a string of ripe 

 ova. They are more likely to be seen than the testes. 



(2) The two oviducts open internally on the anterior face 

 of the septum between 13-14, and externally on the 

 ventral surface of segment 14. Into the wide ciliated in- 

 ternal mouths, which lie opposite the ovaries, the ripe eggs 

 pass. 



