OVARY AND INTRA-OVARIAN EGG IN TELEOSTEANS. 305 



My account of the small ova, therefore, simply becomes one of 

 their transformation into great ova at the time when the latter are 

 extruded. 



In the spent ovary, then, where a few great ova still remain, the 

 small ova of the past year are seen to present two distinct appear- 

 ances ; one that of fig. 4, the normal, and another a much-vacuoled 

 condition, seen in fig. 7. In both I find signs that the ova do at 

 this stage divide. I have chosen figs. 7 and 8 to represent this, both 

 being taken from the same section. There is a considerable amount of 

 variation in the sizes of the eggs of each condition, but from a series 

 of careful measurements I do not distinguish any difference between 

 the average sizes of sufficient importance to be worthy of mention as 

 of significance. It will be noticed from the figures that the non- 

 vacuoled ova have the nucleus with its nucleoli present in the 

 ordinary position, whereas in the vacuoled eggs the nuclear mem- 

 brane has no nucleoli in connection with its inner surface. I have 

 examined a large number of slides showing ova in this condition, but 

 only on one occasion have I found a slight trace of nucleoli. They 

 appear in the normal position, but are extremely small in size, and 

 have apparently atrophied. In a few eggs, which show what I may 

 perhaps describe as an inclination to become vacuoled, the nuclei are 

 already considerably reduced. I further notice that for the most 

 part the vacuoled eggs lie at the surface of the ovary, the normal or 

 fully nucleated eggs being towards the centre in the vicinity of the 

 germinal epithelium. I am convinced that the vacuoled eggs break 

 up simultaneously with the few remaining great ova. There is pro- 

 bably a double significance of this curious condition. The fact that a 

 limited number of great, and very many small eggs should break up at 

 the same time may go to show that the old eggs are not present in 

 the spent ovary, simply because they could not be extruded, but 

 because they may be useful as pabulum, and that there are a super- 

 abundance of small eggs formed from the epithelium at an early 

 stage. It is somewhat difficult to estimate with any degree of 

 accuracy the number of eggs present in an unripe section, although 

 in the case of the riper organ there may be less difficulty. Num- 

 bers no doubt vary in different individuals ; but it seems probable 

 that even with the great enlargement of the organ and the filling 

 up of the central cavity in ripening ovaries there is not room 

 enough, after the great eggs are gone, for a sufficient number of 

 new developing minute ova. At this stage, at any rate, the debris 

 of the organ is added to by the breaking up of a certain number of 

 the ova under consideration, and I take it that the products must 

 either be used for the nourishment of the coming stroma, or are 

 gradually got rid of by extrusion. In the normal eggs of this stage 



