56 Illinois State Laboratory of Natural History. 



The shape of the coecum varies occasionally, and may be cut 

 up into irregular lobes. Quite frequently the receptacles are 

 carried through the aperture in the lower part of a septum, 

 and appear in a somite to which they do not belong. 



Attached to the anterior face of the dissepiment, between 

 somites 9 and 10, is a large, white, irregularly-lobed mass on 

 each side of the alimentary canal, — the seminal vesicles. No 

 lobes or ducts from these vesicles, passing through the septum, 

 have been found, and no means of communication between the 

 vesicles and the other male genital organs have been noted. It 

 is possible, however, that in some conditions of these organs 

 such lobes or ducts may exist, or, possibly, such communication 

 may be by means of pores through the dissepiment. In worms 

 more than half grown somites 10 and 11 are always found 

 loosely filled with spermatozoa. These loose masses may have 

 an extremely delicate membranous covering and represent 

 lobes of the seminal vesicles, but no trace of such membrane 

 has been seen either in sections or by the ordinary means; and it 

 seems safe to assume that these somites are used simply as res- 

 ervoirs for the temporary storage of the male element. In 

 somite 12, on each side of the intestine, is a large white mass 

 consisting of numerous berry-like lobes, the whole attached by 

 a small area to the posterior side of the dissepiment between 

 somites 11 and 12. Often they embrace the intestine and meet 

 above it. These have been regarded as the testes because an 

 examination of their contents shows them to contain the sper- 

 matozoa in various stages of development. No means of com- 

 munication between these bodies and the somites in front of 

 them has been observed, but doubtless the matured product is 

 discharged through the septum to which the testes are 

 attached. The spermatozoa are certainly not set free in the 

 cavity of the somite in which the testes lie. 



The vasa deferentia receive the spermatozoa by two pairs 

 of large flared openings, one each in somites 10 and 11. They 

 lie upon the floor of the somites, within the nephridia, one on 

 each side of the nerve ganglia. The vasa deferentia, passing 

 from them, at once plunge into the integument and become 

 embedded in the thick inner layer of muscle of the body-wall. 

 The vasa uf each side soon meet, and thence continue side by 



