324 Dr Martin Barry on Vesicles in ihe 



letter from Dr Keber informing me that he adopts it. He 

 adds, that on becoming acquainted with my observations on 

 the escape of ovisacs in the Hog, he examined several of 

 these animals slaughtered by the butcher, and in the very 

 first of them found three escaped ovisacs on the outside of 

 the Fallopian tubes. 



My health not admitting of much labour in microscopic 

 research, I have lately requested for this purpose the assist- 

 ance of a friend. He first examined two unimpregnated 

 rabbits, recording and reporting the results, which I quote 

 in his own words. In one rabbit, he says, " I found no trace 

 of escaped ovisacs ; but removed as many as fifteen without 

 any difficulty from different parts of the ovaries. They were 

 of various sizes, §'" and under. They all were fibrous, .... 

 contained one, two, or three ova, and were sufficiently clear 

 to shew the ovum within when gently flattened.' 1 The other 

 rabbit, five months old, he was informed had never had con- 

 nection with the male. He brought me two vesicles from 

 this rabbit. One of them, A, he says, " was still in the ovary, 

 but formed a translucent glistening projection upon the sur- 

 face. Its escape was almost spontaneous after the inclosing 

 ovarian membrane had been torn." We examined this 

 vesicle together. It was elliptical, about §"' in length, and 

 fibrous. It contained three ova, one of them well formed, 

 the others smaller and apparently aborted. This vesicle was 

 evidently an ovisac, freed from its vascular covering. The 

 other vesicle, B, my friend remarks, " was lying at one ex- 

 tremity of the ovary, slightly attached to its surface, with 

 the infundibulum in close proximity. There was therefore 

 left upon its removal " [from the surface of the ovary] " a 

 minute torn or abraded spot." Our joint examination of this 

 vesicle yielded the following results, which are important as 

 shewing in what respects a vesicle, B, attached to the surface 

 of the ovary, resembled, and in what respects it differed from 

 an ovisac (the vesicle A) almost spontaneously escaping from 

 that organ. In size, B rather exceeded A, but had a diameter 

 of less than a line. In the fibrous structure of their mem- 

 brane, and in their elliptical form, B and A did not differ. 

 There was neither " zona pellucida " nor anything that could 



