322 Dr Martin Barry on Vesicles in the 



Bird, &c. This capsule is analogous to the Graafian follicle 

 of Mammalia. The Graafian follicle is therefore not a struc- 

 ture peculiar to Mammalia, as had up to 1838 been supposed. 

 The said originally independent cell — the foundation of both 

 Graafian follicle and capsule — I proposed to call the ovisac. 



There are several points connected with the ovisac to 

 which, on this occasion, I ask particular attention. 1. The 

 capillaries in ramifying on the ovisac often include minuter, 

 or as I called them parasitic ovisacs, which thus come to lie 

 between the membrane of a large one and its vascular cover- 

 ing. I once counted more than fifty in such a position in the 

 capsule of a bird. 2. The ovisac readily admits of removal 

 from its vascular covering, which, however closely applied, 

 does not become connected, — there is no penetration of its 

 membrane. 3. When research of the minutest kind is made 

 on the mode of origin of the ovisac, its young membrane is 

 found to be made up of nucleolated nuclei, which later stages 

 shew to have had within them the elements of fibre. 



In 1839 I published the following fact.* An ovary of the 

 Hog, with a high degree of vascularity in all the parts, pre- 

 sented three ruptured Graafian follicles, with four on the 

 point of bursting. None of these were distended beyond a 

 moderate size. Bloody strings of a fleshy substance were 

 hanging at the orifices of two out of the three ruptured 

 Graafian follicles. In the infundibulum of this side there 

 were several of the same kind of bloody masses of a string- 

 like form, suggesting the idea of their having been rolled-t 

 Some of the string-like masses found in the infundibulum, 

 as well as those pendent at the orifices of the ruptured Graa- 

 fian follicles, on being examined with the microscope, pre- 

 sented a multitude of ovisacs, varying in size from ^Y" an( i 

 less to \'". Of one of these, and of its ovum, I gave a draw- 

 ingj. I added, " The presence of such objects in the infun- 

 dibulum appears to be not un frequent in the Hog. I have 

 observed them also in the Cat."§ 



* Phil. Trans., 1839, pp. 319, 320. 



t In connection with the rolled appearance of these masses, I referred to the 

 muscular state ut certain periods of the middle coat of the infundibulum. 

 J Phil. Trans., 1839, PI. V., fig. 102. § II.., p. 320. 



