447 



and semi-opaque centre, moving freely on each other, and pre- 

 senting the Brownian movement. 



b. Bodies of larger size, strongly refractive, varying in dia- 

 meter, and evidently oil-globules. 



c. Vesicles of various sizes, round, oval, and elliptical, some 

 presenting coarsely granular contents, others extremely fine, 

 almost homogeneous, contents, their borders uniformly clear, 

 dark, but fine, and readily seen ; these vesicles were, some as 

 large as ordinary cells, others as small as nuclei. In none could 

 I detect anything like a nucleus or nucleolus. 



2. A portion of the germinal membrane was found to pre- 

 sent — 



a. Numerous granules, but in much less quantity than in the 

 body of the yolk ; they were also clearer and more transparent. 



b. Vesicles of various sizes, with fine pale contents, and clear 

 but well-defined border, occasional oil-globules, granular cor- 

 puscles, with large, dark, spherical contents, and well-defined 

 dark border. These corpuscles varied much in size ; aggre- 

 gated masses of granules existed here and there, both of the 

 light and dark variety of granules, and with corpuscles im- 

 bedded in them. 



In no case did I see a distinctly nucleated cell in this pre- 

 paration, many vesicles contained a central mass of spherules, 

 but no distinct nucleus. The superposition of granules or ve- 

 sicles is very likely to be mistaken for nuclei or nucleoli; occa- 

 sionally a motion in the fluid disturbs the granules, and they 

 may then be seen to float freely away. I have often observed this. 



3. In a preparation from near the germinal centre, after 

 about twenty-four hours' incubation, the vesicles were much 

 larger, more clearly seen, and very finely granular for the 

 greater part ; a few presented central spherules, with or with- 

 out granules, but I am doubtful, for the reasons just assigned, 

 whether they are to be regarded as nuclei ; a few coarsely gra- 

 nular vesicles were to be seen ; also, isolated and aggregated 

 granules. 



