DR. MARTIN BARRY'S RESEARCHES IN EMBRYOLOGY. 309 



fluid did not appear perfectly pellucid, but presented an indistinct cloudiness. In 

 one of the larger vesicles there was observed a well-marked spot (fig. 1. b.). The 

 envelope of granules, g, was in all instances elliptical, its long diameter being about 

 three times that of the vesicle it surrounded. 



15. In the same Plate, figs. 18 and 19, from the Pigeon, are seen vesicles of the 

 same kind containing fluid, some of them surrounded by oil-like globules, and others 

 by granules of the same appearance as those in fig. 1, having mixed with them a few 

 oil-like globules ; the chief difference being that here the form of the whole object is 

 not quite so regular as that of those in fig. 1. It will be observed that in fig. 18. the 

 vesicles are surrounded by oil-like globules only (*) ; the envelope of peculiar granules 

 seems to be subsequently added (fig. 19. g.). 



16. In figs. 2. and 3, g, are presented elliptic masses of the same kind of peculiar 

 granules. One of these masses (fig. 2. g,) measured ^Vth, and the other (fig. 3. g.) 

 V-c-th of a line in length. These objects, met with in the Cat, appear to have been of 

 the same nature as those just described from the Rabbit and the Pigeon, with this 

 diflference, that here the contained vesicle was not seen; the cause of which is perhaps 

 referrible to oil-like globules having been mixed in large quantity with the peculiar 

 granules. See figs. 2. and 3 (*). That these elliptic masses from the Cat (figs. 2. and 3.) 

 corresponded to those from the Rabbit and the Pigeon, and that each of them con- 

 tained a vesicle, is not indeed demonstrable ; but their form, their size, and the na- 

 ture of the granules render this extremely probable. I should add, as another reason 

 for this opinion, that patches of these elliptic masses (figs. 2. and 3.) have been met 

 with, sometimes in the state g, and sometimes in that marked (*). Similar objects have 

 been seen in the Hog-f-. 



17. I have found distinct vesicles in the Salmon, measuring in diameter the 50th 

 of a Paris line J, and less (Plate VI. fig. 30. c), apparently corresponding to those from 

 the Rabbit (Plate V. fig. I.e.) and Pigeon (figs. 18. and 19. c), but having more obscure 

 contents §, and being destitute of a regularly formed envelope of granules. 



18. I return to figs. 1, 18, and 19, Plate V., from the Rabbit and the Pigeon, and 

 shall not refer to any besides these in drawing my conclusions. After an attentive ex- 

 amination of these objects, I -do not think it hazardous to express my belief that they 

 present one of the earliest stages in the formation of the ovum, the enveloped sac 

 (c) being, as I suppose, the germinal vesicle itself. 



1 9. The long diameter of this vesicle (c) in fig. 1, the stage now imder consideration, 

 varies, as already said, from the 150th to the 50th of a Paris line. It is not likely 



t In one of the Mammalia I have seen vesicles filled with fluid, and apparently of the same kind as those in 

 fig. 1, but without any peripheral accumulation either of granules or oil-like globules. These vesicles, how- 

 ever, were immediately lost from the field of view, and I have not since observed any in the same state. 



+ =r -5-I-2- of an English inch. 



§ Which consisted of a fluid and minute oil-like globules, having a yellowish colour. Compare the vesicles 

 in this figure with the vesicles (c) in fig. 35. from the same animal. 



One of the vesicles (c) in fig. 30, has another vesicle external to it. (See Explanation of the Plates.) 



