OVARIES IN TELEOSTEAN AND ELA8M0BRANCH FISHES. 213 



structure, with no well-defined limit on the side of the follicular epithelium. 

 Irou hsematoxylin and orauge G. X 400. 



Fig. 31, — Spinax niger. Part of a transverse section of a corpus luteum 

 from the ovary of a female in which the young were almost ready for birth, 

 showing hypertrophied follicular epithelium invaded by radial invaginations of 

 thecal connective tissue bearing venous blood-vessels. Iron hsematoxyliu. 

 X 130. 



Fig. 32. — Spinax niger. Portion of the same "corpus luteum" more 

 highly magnified. Iron h. X 400. 



Pig. 33. — Spinax niger. Nuclei from the theca foUiculi of the same 

 "corpus luteum," showing stages in amitotic division, x 450. 



Pig. 34. — Zeus faber. Section at the surface of an immature egg, 

 showing three definitive egg membranes and a zonoid layer, x 420. 



Pig. 35. — Sygnathus acus. Section of a series of small ova near tlie free 

 edge of the ovigerous lamella, showing deudritic appearance of the] "yolk- 

 nucleus " around the germinal formic- formol-alcohol mixture, x 130. 



Fig. 3G. — Sygnathus acus. Section of small ova near the edge of ovi- 

 gerous lamella, showing the effect of Perenyi's fluid in dissolving out the 

 "yolk-nucleus." X 130. 



Pig. 37. — Zeus faber. Section of immature ovum, showing the relation 

 of the "yolk-nucleus" to the oil droplets. The latter are represented iu the 

 figure by minute circles. 



