DR. MARTIN BARRY'S RESEARCHES IN EMBRYOLOGY. 337 



surface of the membrana vitelli. Compare with fig. 25. Plate V. from 

 the common Fowl, and fig. 16. Plate V. from the Hog. 240 diam. 



Fig. 35. Salmon (^Salmo Salar, Linn.). Ovisacs and their contents in nearly the 

 same state as those in the last figure, g. Some of the peculiar granules 

 (8.) are seen in the fluid of the ovisac (34.). Compare with fig. 25. 

 Plate V. from the common Fowl, and fig. 16. Plate V. from the Hog. 



Fig. 36. Ditto. The ovisac {h) acquiring a proper covering or tunic {i) (47.). In 

 this instance two minute ovisacs are included by the covering (57.)> their 

 situation here being within the incipient pedicle. 100 (?) diam. 



Fig. 37. Ditto. The same objects (A i) in a more advanced stage, but the cover- 

 ing still very transparent. The vesicles have been crushed, and the yelk 

 is seen escaping through the pedicles, taking with it its proper mem- 

 brane (e). 25 diam. See the ideal section, Plate VI. fig. 38J. 



Fig. 38. Ditto. The perfect calyx with its pedicle. 25 diam. 



Fig. 38J. Bird, &c. Ideal perpendicular section of that portion of the ovary which 

 is called the calyx, and its contents, d. The yelk surrounded by its 

 proper membrane, e; h. lining membrane of the calyx. (This lining 

 membrane of the calyx was originally the independent ovisac.) i. Vas- 

 cular covering or tunic of h. (By the union of h and i there is constituted 

 h i, that portion (capsule) of a calyx which is analogous to the Graafian 

 vesicle of Mammals.) k. Substance of the ovary ; /. peritoneum ; i, /r, and 

 ■ / are reflected off from h, thus forming a pedicle / k I. This pedicle 

 is comparatively hollow, so that when the calyx is crushed, a portion of 

 the yelk (meeting with least resistance at the point where the reflectioi 

 above-mentioned takes place,) escapes into it. 



Fig. 39. Dog {Cams familiaris, Linn.). Granules (§•) of the Graafian vesicle cir- 

 cumscribed by a distinct line (central portion of the retinacula?). 

 g*. Isolated spots ; g^. membrana granulosa ; g\ tunica granulosa ; h /. 

 Graafian vesicle. 60 diam. 



Fig. 40. Mole {Talpa europcea, Linn.). The same objects with the exception of ^*. 



Fig. 41. Ditto. The tunica granulosa {g^) in the course of formation (68.). h. Ovi- 

 sac ; i. blood-vessels ; h. germinal spot (of a yellowish colour) ; c. ger- 

 minal vesicle ; d. yelk ; f. chorion. 440 diam. 



Fig. 42. Ditto. The tunica granulosa {g^) removed entire from the Graafian ve- 

 sicle, c. Germinal vesicle in the centre of {d) the yelk ; f. chorion. 



Fig. 43. Sheep {Ovis Aries, Linn.). The tunica granulosa removed almost entire 

 from the ovisac, b. Germinal spot ; c. germinal vesicle ; d. yelk ; f. cho- 

 rion. 240 diam. 



Fig. 44. Dog {Canis familiaris, Linn.). The tunica granulosa {g^) very highly 

 magnified ; most of its granules presenting very distinctly a nucleus, and 

 some of them being very globular in form (9.). d. Yelk ; f. chorion. At 



MDCCCXXXVIII. 2 X 



