EAETHWOEM 71 



when killed. Three pairs, in which somites? They contain 

 spermatozoa. 



2. Ventrally the sperm sacs are connected by a common 

 seminal vesicle. 



3. The testes, two pairs in X and XI, in positions corre- 

 sponding to those of the ovaries in XIII, are small and being en- 

 closed in the seminal vesicle they cannot be seen. 



B. Female Reproductive Organs 



1. The ovaries are attached to the anterior septnm of XIII 

 near the mid-ventral lines. They are generally difficult to find. 



2. Oviducal funnels are on posterior septum of XIII op- 

 posite the ovaries. 



3. The oviducts lead from them backwards to the ventral 

 wall of XIV. 



4. Spermathecae, two pairs of small globular sacs lying 

 close to the septa between IX and X, and X and XI. They open 

 to exterior on ventral side and receive spermatozoa from another 

 worm. 



Make a diagram of a side view showing the location of the 

 reproductive organs found. Number segments. 



C. Reproduction in the Earthworm 



Because the earthworm has the reproductive organs of both 

 sexes functional in the same individual it is said to be hermaph- 

 roditic. During the breeding season earthv;orms come out of 

 their burrows at night for the purpose of copulation. Two in- 

 dividuals come together with their heads pointing in opposite di- 

 rections. While in this position a mucus tube is secreted which 

 holds the two worms with their ventral surface together. 



During this period of copulation, glands in each clitellura 

 secrete a cocoon which surrounds the body of the worm. Into 

 each cocoon, spermatozoa and eggs are deposited. Fertilization 



