116 J. T. CUNNINGHAM. 



ovary appeared from its size and flaccid condition to have 

 previously spawned. The tissue was opaque white, and the 

 microscope showed it to contain numbers of partially yolked 

 eo-^s, the largest of which was '5 mm. in diameter. In 

 sections prepared from this ovary no trace of degenerating 

 follicles can be seen. They are also absent in sections from 

 an ovary of a large plaice killed on August 25th, which was 

 known to have spawned the previous season, having been kept 

 under observation. in the aquarium. 



A female flounder which spawned in March in the aquarium 

 was killed on July 11th. The ovary contained only trans- 

 parent yolkless ova — that is to say, the formation of yolk in the 

 eofgs to be shed in the following spawning season had not 

 commenced. But in prepared sections a few remnants of the 

 degenerating follicles from the previous spawning could be 

 discovered. It may be concluded, therefore, that in plaice and 

 flounder the ^'corpora lutea '^ are entirely absorbed in about 

 three or four months. 



In preparations from portions of the ovary of a spent sole, 

 preserved on board a fishing vessel fifty miles eastward of the 

 Humber, on July 24th, the degenerating follicles are numerous 

 and distinct. They are, however, small and solid, the cavity 

 having been obliterated. This ovary contains only a compa- 

 ratively small number of yolkless ova, the production of new 

 eggs having not yet taken place to any considerable extent. 

 The spawning of soles in the North Sea takes place chiefly in 

 May and June. In preparations from a sole taken off" Lowe- 

 stoft, on September 24th, the degenerating follicles cannot be 

 detected, but there are distinct though small remnants of them 

 in sections from a specimen obtained on September 20th. 



Tn a haddock 19 inches long, portions of whose ovary were 

 preserved at sea immediately after death on July 23rd, the 

 empty follicles had been entirely absorbed. The haddock 

 spawns in the North Sea principally in March, and there are 

 no immature specimens over 16 inches long. 



