OVARY AND OVARIAN OVA IN CERTAIN MARINE FISHES. 119 



one which is undergoing retrogressive change. Neither in 

 these nor in the neighbouring normal ova can yolk granules 

 be distinctly recognised^ but there are a few vacuoles which 

 probably represent small oil globules. The chief abnor- 

 mality in the degenerating ova is the condition of the ger- 

 minal vesicle, which consists of one large nucleolar mass ; 

 the rest of the vesicle, membrane and clear contents, having 

 disappeared almost entirely. In the central part of the ovarian 

 lamellae were distinct masses of irregular shape and yellowish 

 colour, which had not taken the stain of the hsematoxylin. 

 These consisted of yolk-like substance, with nuclei scattered 

 through it. Each was surrounded by connective-tissue fibres, 

 but not by a distinct follicular wall. These masses are the 

 remains of eggs which had reached an advanced stage of 

 maturation when spawning took place, and which have been in 

 great part reabsorbed. It is evident, therefore, that in the 

 spent ovary, eggs in various degrees of development die, and 

 are absorbed. 



On September 17th I examined, in the fresh condition, an 

 ovary of the greater weever in which spawning had more 

 recently occurred, and in which, therefore, the reabsorption of 

 abortive ova had scarcely begun. Its condition supports the 

 interpretation given above. It contained (1) perfectly trans- 

 parent yolkless ova, (2) slightly opaque, apparently healthy 

 eggs containing a zone of granules, (3) dark yellowish granu- 

 lar masses, without refringent globules, evidently dead eggs 

 which had not been ripe when spawning was completed, and 

 (4) large rounded masses, quite opaque, and containing large 

 oil globules ; these were evidently eggs which had nearly 

 reached the ripe condition before they died. 



Reabsorption of Aborted Eggs in Immature 



Ovaries. 



I at first supposed that the opaque granular masses, identi- 

 fied as partially matured but aborted ova, only occurred in 

 spent ovaries. But it was afterwards found that thev occur 



