John P. Munson 325 



ing reaction. A center, like that represented in Plate IV, Fig. 69, can 

 be differentiated by acid fuchsin following hasmatoxylin so that alone 

 stands out like a bright red astral body, all other parts of the cell retain- 

 ing the haematoxylin stain. 



All parts of the germinal vesicle take the hseraatoxylin stain, and 

 retain it after application of acid fuchsin or eosin. The granular matrix 

 of the germinal vesicle has a paler coloration while the nucleoli are most 

 deeply colored by this stain. When haematoxylin is followed by picric 

 acid, the granular matrix is strongly affected, while the nucleoli resist its 

 action, as does also the chromatin network, especially the spherical 

 chromosomes (Plate IV, Figs. 67, 68). Haematoxylin has very little 

 effect on the cytocenter. Appearances like those represented in Plate II, 

 Figs. 27, 41, are apparently frequent after this stain. When haema- 

 toxylin is followed by acid fuchsin, the cytocenter is the most conspicuous 

 part of the section. 



Forms like those represented in Plate II, Figs. 29, 45 ; Plate IV, Fig. 

 66, are made conspicuous by eosin. A cytocenter of an egg about the 

 size of that represented in Plate II, Fig. 49, from a section stained with 

 eosin, is represented in Plate VII, Fig. 90, as it appears under a high 

 power. That it has the essential structure of the original centrosome 

 and sphere of the very youngest eggs, as that represented in Plate I, 

 Fig. 17, for instance, is quite evident. Owing to the great increase of 

 the amorphous granules of the cytolymph, the fundamental structure is 

 obscured. But it can, nevertheless, be seen that it consists, as in the 

 young egg, of a darker center surrounded by a less dark ring; and this, 

 again, surrounded by definitely limited zones, which again are surrounded 

 by a wider zone of open meshes of fibers apparently in the form of a 

 network. Through this outer network of fibers there can also be seen 

 radial fibers proceeding from the inner zones. I have taken special pains 

 not to exaggerate these features in the section. It is hardly necessary 

 to say that an exact reproduction, in pencil drawings, is difficult if not 

 impossible. Yet Plate VII, Fig. 90, is as near a true picture as I can 

 hope to make it. I feel confident that everything represented in the plates 

 can be seen by any unprejudiced eye, from the slides from which the 

 drawings are made. Indeed, realizing the danger of subjective elements 

 in seeing, I have taken pains to have disinterested parties criticise my 

 drawings from an inspection of the preparations. 



Stage III. 



The germinal vesicle retains its spherical form, and increases in size 

 with the growth of the egg. Its size, however, does not seem to be con- 

 24 



