SEA-FISHEEIES LABORATORY. 135 



marginal part of the ovary, forming a concentric internal 

 capsule, which has then shut off the mass of ova internal to 

 it from the circulation of nutritive fluid in the ovarian sac. 

 In the closed ovarian sac of the teleostean fish the blood 

 vessels are mainly contained in the serous and fibrous layers 

 external to the germinal epithelium. This germinal epithelium 

 projects inwardly, as radial septa, towards the centre of the 

 ovary, and lymph diffuses out from the blood vessels running 

 in these septa, and forms the fluid of the ovarian sac. If a 

 non-permeable capsule were to form all the mass of ova within, 

 it would be shut off from this lymph diffusion, and might 

 possibly cease to mature and break down, both structurally 

 and chemically. The ground substance shown in fig. 3 

 might therefore represent the altered yolk and other substances 

 of the ova, and the blue bands might be sections of the more 

 resistant capsules of the eggs. 



On this view some progressive change has therefore 

 occurred in the ovary, it may be a sarcomatous condition 

 resulting from the over-growth of the connective tissue of the 

 ovarian stroma in a marginal, concentric zone of the organ ; 

 and this progressive change has been accompanied with a 

 retrogressive change, and chemical alteration of the substance 

 of the ova. 



The whole thing indeed suggests a dermoid cyst. With 

 this idea I searched through it for traces of cuticular or 

 epidermal structures, such as scales, but nothing of this kind 

 could be recognised. 



The Chemical Nature of the Deposit. 



This has not been fully determined. A part from the 

 inside of the deposit, as nearly homogeneous as possible, was 

 cut into slices and dried at 100° C. The dried material was 

 hard and horny, and did not shrink much (dried at 110° C. the 

 material gave 30*9 % of moisture). On heating the dried 



