156 OVARIES OF FISHES. 
protoplasm. It is worthy of note that in the ovary of the plaice, 
when spawning commences, the ripe eggs are scattered here and 
there uniformly throughout the germinal tissue, not confined to 
one place. In other words one part of the ovary does not get 
ripe before another, but in all parts the eggs ripen in succession, 
until all are shed. 
When all the eggs of the season have been shed the ovary is 
found in a flaccid, empty condition, the germinal tissue on the walls 
of the ovary being thin and containing much blood. The fish is 
now spent. ‘The first specimen I found in this condition last season 
was obtained on January 28th. The specimen was 24 inches long ; 
the ovary had not shrunk greatly in length, it was 73 inches long, 
measuring from the anterior end of the ventral fin, and the end 
of it was 4¢ inches from the posterior end of the same fin. In 
the internal cavity of the ovary a number of detached, ripe eggs 
were found ; these were dead, but fresh, and seemed to have shed 
after the death of the fish. No ripe or nearly ripe eggs remained 
in the stroma or germinal tissue of the ovary. When a portion of 
this tissue was examined it was found to consist chiefly of trans- 
parent, yolkless ova exactly similar to those seen in the immature 
fish, but besides these there were scattered here and there singly, 
ova which showed a thin layer of yolk granules round the periphery. 
The appearance of the eggs from a small portion of the germinal 
tissue is Shown in Fig. 1. The yolked eggs were somewhat opaque and 
Fia. 1.—Eggs in the ovary of a spent plaice. a, yolkless ova; 6, yolked ovum 
destined to degenerate. 
presented a dull, unhealthy appearance. The smallest of the yolked 
eggs was ‘27 mm. in diameter, and the largest of the yolkless eggs 
very little smaller; the largest yolked eggs were °36 mm. in 
diameter, I was at first inclined to interpret this condition as 
