204 OVARY AND PAROVARIUM, BY W. WALDEYER. 



tion. Additional historical data upon the corpora hi tea may 

 be found in the dissertation of Zwicky (129). 



Not all the Graafian follicles, the number of which is esti- 

 mated by Henle in a young ovary at 36,000, and by Sappey 

 (see Frey, 40, p. 534) at 400,000, attain maturity ; and a few- 

 only furnish a ripe ovum. By far the greatest number die 

 away at the most diverse periods of development; even the 

 smallest follicles may be met with in a state of atrophy, as 

 Pfliiger has also observed (84). In the large atrophied follicles 

 the remains of the ovum occur for the most part in the form of 

 a very thick, highly refractile, compressed zona pellucida, with 

 a small quantity of granular contents. The follicular wall 

 undergoes alterations similar to those that occur in the forma- 

 tion of the corpus luteum, except that the neoplastic material 

 is smaller in quantity. Well-formed corpora lutea occur only 

 amongst Mammals ; in the less developed condition, however, 

 they are present in all Vertebrata, and large numbers of atro- 

 phied follicles may be discovered in all classes of Vertebrata. 



Recent investigations made on Dogs have convinced me that the 

 ovarial epithelium is deficient upon the surface of recently formed 

 corpora lutea ; on the other hand it penetrates very deeply between 

 the ovarial stroma and the periphery of the corpus luteum at the point 

 where the follicle has ruptured. Further observations are required to 

 show whether or no a neoplastic formation of follicles and ova proceeds 

 from these inflections of the epithelium. 



PAROVARIUM (Nebeneierstock). The Wolffian body consists, 

 as J. Miiller long ago demonstrated, and as Banks (7) and 

 Dursy (35) have also shown, of two distinct structures; one 

 consisting of a wide canal, with flattened granular epithelium, 

 that is in connection with glomeruli. This constitutes the 

 primordial renal part of the Wolffian body. The canaliculi 

 of the second portion, that in Man includes the upper part of 

 the Wolffian body, are narrower, and have a more columnar 

 epithelium, which subsequently is in some parts ciliated. These, 

 in the human subject, develop into the canaliculi of the head 

 of the epididymis. In the female they penetrate to the hilus 

 of the ovary, and in many species of animals, as in the Dog 

 (fig. 191), the Cat, and the Cow, deeply into its stroma. They 



