No. 6.] DEVELOPMENT OF PARYPHA CROCK A. 295 



endoderm. No gonophores from which the sperms had been 

 expelled were found, so I was unable to prove that this repre- 

 sented the ectoderm of the manubrium, but as that layer was 

 not observed in the female until a very late stage, I think that 

 there can be little doubt that it functions as such. 



Origin and Morphology of the Female Gonophore. 



The female gonophores arise in the same manner as the 

 male and, in the early stages, are made up of the same parts, 

 but later may always be distinguished by a circle of six or 

 eight short, blunt tentacles at the distal end and by their 

 more elongated shape. When filled with young they are 

 nearly spherical and the tentacles mere papillae ; but when the 

 larvae have been set free the medusoids become elongate and 

 the tentacles expand. PI. I, Fig. 5, shows a section through 

 two of these tentacles. 



Oogencsis. 



The primitive egg cells are developed in the same manner 

 as the sperm mother-cells. I find no evidence whatever of ova 

 either in the coenosarc of the stem, the body of the polyp, or 

 the walls of the peduncle. There are in the endoderm of the 

 polyp and peduncle numerous large, deeply stained cells with 

 large nuclei which somewhat resemble eggs when cut in the 

 right plane, but a careful study of a large number of sections 

 reveals the fact that they are in reality highly differentiated 

 endodermal cells. They are always in contact with the sup- 

 porting layer and usually project beyond the other endoderm 

 cells into the body cavity, neither of which conditions, accord- 

 ing to Weismann ('83), p. 70, occurs in egg cells. Moreover, 

 these cells are much larger than the primitive ova and take a 

 deeper stain than do the eggs in any stage of their develop- 

 ment. They are very rich in protoplasm, and sometimes the 

 outer surface is found sloughing off into the body cavity. 

 This condition was even more marked in similar cells in 

 Eudendrium ramosum, where they extend farther into the body 

 cavity, and the discharge of portions of their protoplasm was 



