212 WILLIAM WALLACE. 



tlieliiim, and containing liie fatty degeneration products of tlie egg. Borax 

 carmine. Zeiss A, ocular 4. 



Fig. 22. — Zoarces. Section of an aborted follicle, showing proliferated 

 follicular epithelium bursting through the softened zona. Remains of tlie egg 

 (v. ei.) are seen in the centre, invaded by free cells derived from the follicular 

 epithelium. That part of the follicular epithelium which lies inside the zona 

 is charged with fat. Borax carmine, x 90. 



Fig. 23. — Zoarces. 13"3 cm. Sept. 15. Section of an abortive follicle, 

 showing a later stage in the absorption of the egg. The ovigerous pouch is 

 much contracted, and scarcely projects beyond the general surface of the 

 ovary. The theca folliculi is greatly thickened. In the centre is a mass 

 of yellow granules, amongst which are scattered white blood-corpuscles and 

 nuclei of doubtful origin. Carmalum. x 400. 



Fig. 24. — Zoarces. Semi-diagrammatic longitudinar section of an ovi- 

 gerous pouch from which an egg has recently escaped. From an ovary of 

 August 19th. 



Fig. 25. — Zoarces. Longitudinal section of a " villus " from a pregnant 

 ovary in February. On the same scale as last figure. 



Fig. 26. — Zoarces. Transverse section of a "villus" in the plane of a b 

 of Fig. 25. On the same scale. 



Fig. 27. — Zoarces. Section of a portion of a " villus" from an ovary of 

 October. The egg cavity is much compressed, and the follicular epithelium 

 has not proliferated. Zeiss A, ocular 4. 



PLATE 17. 



Fig. 28. — Chimse ra monstrosa. Section at the surface of an immature 

 ovary, showing young follicle with membrana propria folliculi enclosing a 

 follicular epithelium, consisting of small cells, also two large cells, of which 

 the one to the left is certainly an ovum, while the smaller one to the right is 

 probably a " nutritive " cell like those in Figs. 29, 30. Iron hematoxylin and 

 orange G. x 400. 



Fig. 29. — Chimsera monstrosa. Section at the surface of an egg, about 

 4 mm. in diameter, nearer the animal pole, showing the many-layered follicular 

 epithelium with differentiation of its elements; small cells on the side of the 

 follicular membrane and large " nutritive" cells on the side of the egg. The 

 egg membrane is here thin but dense, and clearly limited on both sides. 

 Zonoid layer as in Zoarces. Streams of nutriment passing into the yolk are 

 indicated. Iron hematoxylin and orange G. X 400. 



Fig. 30. — Chimsera monstrosa. Section at the surface of the same egg, 

 but nearer the vegetable pole, showing the long-drawn-out processes of tiie 

 follicular cells passing through the substance of the much modified egg mem- 

 braue. The latter is much deeper than in Fig. 29, and iias an open fibrous 



