74 J. T. CUNNINGHAM. 



capsules were visible. There was a stroma of connective tissue 

 in which were large irregular spaces containing nucleated 

 cells, and I concluded that this was an abnormal case in 

 which cellular hypertrophy of the testicular portion had taken 

 place. It was a case probably in which the testicular portion 

 present normally in the young state, had, instead of being 

 absorbed, undergone a kind of cellular degeneration accom- 

 panied by hypertrophy. 



Summary. 



The firm membrane enclosing the ripe deposited ovum of 

 Myxine is a primary egg membrane produced within the 

 follicle. 



The polar threads are processes from this membrane. 



The membrane is single and not diflFerentiated into layers : 

 it possesses minute pores perpendicular to its surface, and is 

 therefore a zona radiata. 



The zona radiata in Myxine is homologous with the single 

 or double zona radiata of Teleosteans and of Petromyzon. 



The membrane at one pole of the ovum, that at which the 

 protoplasmic germinal disc is situated, is perforated by a 

 micropyle. 



The micropyle is produced by a process from the follicular 

 epithelium. 



The immature testis in Myxine consists of a thickened 

 border of the mesorchium containing more or less spherical 

 capsules, which are filled with hyaline nucleated spermatoblasts. 



A large proportion of immature Myxine are hermaphro- 

 dite, the posterior portion of the reproductive organ containing 

 testicular capsules which have the same structure as those 

 found in the male. 



Spermatozoa have been found in the testicular portion of 

 the hermaphrodite organ, but not in the males. 



