OVARIES IN TELEOSTEAN AND ELASMOBEANCH FISHES. 191 



epithelium and egg- membranes at the two poles. This differ- 

 ence is especially striking in Chimtera. Figs. 29 and 30 do 

 not by any means represent the extreme conditions. The 

 follicular epithelium is very much flatter, and the egg mem- 

 brane very much thinner over the place where the nucleus is 

 situated than is represented in fig. 29, a section from the side 

 of the egg, nearer the animal pole, but some distance from it. 

 As Ave pass towards the vegetable pole the egg membrane 

 gradually becomes thicker, and at the same time laxer in 

 structure, until, as in tig. 30, it presents an appearance as if it 

 had been teased out and resolved into its component fibres. 

 As we travel over the surface of the egg towards the animal 

 pole we see how the egg membrane is constituted, viz, by a 

 matting together and condensation of fibrils at the surface of 

 the egg. 



Figs. 29 and 30 are both drawn to the same scale, so that 

 the thickness of the follicular epithelium and egg membrane 

 in the one figure may be directly compared with their thick- 

 ness in the other. We then see that corresponding with a 

 greater thickness and laxer structure of the egg membrane is 

 the greater depth and laxer arrangement of the follicular 

 epithelium. As Ave approach the vegetable pole of the egg 

 the processes of the follicular cells, Avhicli can be distinctly 

 seen to pass through the egg membrane, become moi'e 

 obvious. As the membrane thickens the processes lengthen, 

 and Ave get the condition shoAvn in fig. 30. 'J^lie processes 

 can often be seen to take a spiral course through the mass of 

 fibres composing the egg membrane. In iron ha)matoxy]in- 

 orange preparations these fibres stain Avith the orange like the 

 fibres of connective tissue. Their course is, for the most part, 

 radial Avith respect to the centre of the egg, but they seem to 

 branch and anastomose Avith one another. Although in many 

 cases apparently living protoplasm, granular and staining 

 Avitli hsematoxyliu, can be traced right through from a folli- 

 cular cell to the zonoid layer, in other cases the processes of 

 the follicular cells pass insensibly into the substance of certain 

 of the fibres. I cannot say Avhether there is a gelatinous sub- 



