OVARIES IN TELEOSTEAN AND ELASMOBEANCH FISHES. 197 



impinge directly on the protoplasm of the egg, there being 

 no intervening egg membrane. The nuclei of these cells are 

 larger and more granular than in (Ij. They are orientated 

 so that their long axes are perpendicular to the surface of 

 the egg. The follicular epithelium may present both aspects 

 in different regions of the same egg (fig. 16), so that over 

 one segment of the egg the cells are of the flat variety, 

 whilst over the rest of the surface they are turgid and more 

 columnar. The two different conditions can be easily seen 

 in the fresh ovary. 



At first it was thought that the columnar condition of the 

 follicular epithelium with its large granular nuclei might 

 have some significance in relation to the nutrition of the 

 normal egg. Three facts, however, are against this inter- 

 pretation : — (1) The turgid condition of the follicular epi- 

 thelium is only present in a small proportion of the follicles ; 

 (2) the zona radiata is absent; (3) eggs with follicular 

 epithelium in this condition are frequently collapsed. 



The nests of follicular epithelial cells represented in figs. 

 4 and 5 are probably instances of egg absorption at a still 

 earlier stage. The nuclei of these cells have the aspect 

 characteristic of those of the turgid epithelium just spoken 

 of. 



In sections of the ovary of an immature female 13 cm. 

 long, and caught in February, the ovigerous pouches measured 

 "5 mm. across. The majority of the pouches of this size con- 

 tained normal eggs, with oil globules disposed in two zones ; 

 one around the germinal vesicle in the dense protoplasm 

 there situated, another near the surface of the egg. No yolk 

 spheres were present in these eggs. 



A minority of the larger ovigerous pouches in the ovary 

 under consideration contained degenerate ova. Two stages 

 in the process of absorption, an earlier and a later, are repre- 

 sented in figs. 20 and 21 respectively. The transition from 

 the one condition to the other is easily understood. The 

 earlier condition will first be described. From the size of 

 the pouch in this case (fig. 20) the egg, at the time of its 



