ANNELIDA 



85 



produced. These lead into ducts which amalgamate to form a 

 pair of vasa def erentia which open to the exterior at the fifteenth 

 segment. The sperms are transferred to another earthworm 

 and stored in the spermathecae. The spermathecae are two 



Spermathecae. 



9 

 10 



1 1 



I? 



13 



M 



15 



PIG. 40. Lumbricus. Diagram of reproductive organs. 



pairs of ectodermal sacs, which open in the grooves 9-10, 

 10-11. The two worms approximate from their respective 

 burrows, the head of the one being directed to the posterior 

 end of the other, and lay hold of one another by a double 

 exudation from the clitellum, and their adposed ventral 



FIG. 41. Lumbricus. Sketch of worms to show their position in the 

 act of pairing. 



surfaces are fixed by the capsulogenous glands. Between the 

 two clitella a groove is thus formed, into which the sperms are 

 discharged by one of the worms and from which they are 

 passed into the spermathecae of the other. It is evident that 

 it is not a matter of exchange. 



The female organs consist of a pair of ovaries which are 

 developed from the coelomic epithelium of the front wall of 



