290 



LOUISE HOVT GREGORY. 



Oil 



the body cavity are seen cells still undeveloped, cells almost 

 mature with a thin membrane about them, and cells entirely free. 

 Together with these are found the ova. As a general rule the 

 spermatozoa seem to pass through the greater part of their de- 

 velopment in the organ before passing into the body cavity, while 

 the ova fall into the body cavity in an immature condition and 

 undergo the greater part of their development free from the organ. 

 In a great many cases, spermatozoa could not be found in the 

 organ but were found in great masses in every segment. Ova 



filled the organ and were also 

 free in the body. In other speci- 

 mens spermatozoa were found in 

 the posterior end of the body 

 cavity only, while ova were 

 found in the organ and free in 

 the body cavity. From these 

 observations it appears that the 

 male products develop first in 

 the organ, the development be- 

 ginning at the anterior end of 

 the body. In the cases where 

 spermatozoa were found only in 

 the body cavity, they had already developed in the organ and 

 had become freed. In the cases where they were found only 

 at the posterior end of the body, those at the anterior end had 

 become mature and had passed entirely out of the body. 



A comparison of these results with those found in Ophryolrocha 

 puerilis ' by Eugen Korschelt, shows many similarities as well as 

 differences. In both annelids ova and sperm are found together 

 in the same segment. In Ophryotrocha the sexual products are 

 produced in a gland which has no definite structure, and which 

 is merely a large sac in the body cavity. In Sabclla the sex 

 organ is more definite in outline and form. In this organ the 

 sexual products are formed and develop until they pass into the 

 body cavity where their appearance is similar to the appearance 

 of the sexual gland in Opliryotroclia. In Ophryotrocha the sexual 

 glands are found in about ten segments of the body. In the 



1 Eugen Korschelt, " Ueber Ophryotrocha puerilis Clap. Metschn.," Zeit.f. Wiss. 

 Zool., 1893-94, Bd. 57, pp. 272. 



FlG. 4. Hermaphroditic organ 

 Ov, ova ; sp, spermatozoa. 



