20 JOHNS HOPKINS UNIVERSITY MORPHOLOGICAL MONOGRAPHS. 



made a special study of the ovogenesis, I infer that the constant presence 

 of at least one, points to an origin of the ovum from a syncytium (of at 

 any rate two cells), similar to that which has been recently shown by 

 Doflein ('96) to occur in the formation of eggs in Tubularia. In the 

 nearly mature ovary each ovum is surrounded by a layer of gelatine, 

 which comes from the gelatinous sheet that enters the leaf -like ovary for 

 its support along its line of attachment just internally to the interradial 

 septum. It seems as if the ova, arising in the epithelium on the surface, 

 pushed their way into the gelatine inside and there completed their 

 development entirely surrounded by a slight investment of gelatine, 

 which grows thinner around each ovum as it increases in size. In males 

 the testes always show a similar division into compartments by gela- 

 tinous meshes, the compartments thus mapped out being filled with the 

 small brightly staining spermatocytes. Ova and spermatozoa when 

 mature are set free in the stomach pockets. 



10. Floating and Wandering Cells. In the stomach pockets, the 

 canals of the sensory clubs, and even in the stomach itself, are found in 

 varying numbers freely floating cells having the appearance of young 

 ova. They vary in size, the smallest being of the size and having the 

 general aspect of the small ovocytes found in the ovary. The largest 

 (Fig. 70) have exactly the same structure as the young ovarian eggs 

 before they have begun to accumulate yolk. The granular deeply stain- 

 ing cytoplasm, the clear non-staining nucleus with its bright nucleolus 

 and the nucleolus-like yolk nucleus, all show beyond doubt that these 

 freely floating cells originate in the ovary. 



In some of my preparations these cells are found not only floating 

 free, but wandering through the tissues. Fig. 70 shows two such wander- 

 ing cells fixed just as they were making their way either through the 

 digestive epithelium into the gelatine of the floor of the stomach, or from 

 the gelatine into the epithelium. The former seems the more probable, 

 though why they should want to get into the gelatine is not very easy to 

 conceive. 



Perhaps there is some connection between this and the appearance 

 that the young ovarian eggs have of pushing their way from the epithe- 

 lium into the gelatine of the ovary. And of course it is not impossible 

 that the whole phenomenon is abnormal, due to rupture of the ovaries 

 which sets free young ova to exhibit their amoeboid tendencies under 

 new conditions. Against such an explanation, on the other hand, might 

 be urged the fact that what seem to be the small floating cells are found 



