John P. Munson 321 



increases in amount. The granules causing this turbidity are at first 

 very minute, and do not stain so intensely in nuclear stains as the smaller 

 granules of the germinal vesicle. The cytoreticulum is, however, made 

 evident by such stains as eosin and picro-carmine, and even by haema- 

 toxylin. 



The centrosome retains more or less completely the characteristics 

 which it possesses just after the telophase of karyokinesis of the oogo- 

 nium. It is not always possible to see the tiny central granule. The 

 circle of large microsomes is more easily seen. It encloses a clear, 

 glassy, round opening or globule (Plate I, Fig. II:). The archoplasm 

 surrounding this usually extends to the germinal vesicle, partly enclosing 

 it, thus forming a crescent-shaped granular area, in the widest portion 

 of which the centrosome and sj)here can be seen. The granular archo- 

 plasm sometimes obscures the centrosome structure either partly or com- 

 pletely, in which case only an irregular mass of granules marks the loca- 

 tion of the centrosome. Occasionally, too, the archoplasm flows around 

 the germinal vesicle, forming a ring (Plate I, Fig. 15), at one pole of 

 which the centrosome and sphere are to be seen. This consists of a 

 small central granule, from which radiate tiny fibers in all directions to 

 comparatively large microsomes which, owing to their size, form a dark 

 ring around a light area immediately surrounding the central granule, 

 and across which the slender radiating fibrils extend. From this first 

 ring of large microsomes, there extend similar radiating fibers to a 

 second ring of microsomes slightly smaller than the first and situated 

 about half way between the inner ring and the periphery of the egg 

 (Plate I, Fig. 17). The entire contents of this second ring stain more 

 deeply than the rest of the cytoplasm, but not nearly so intensely as the 

 germinal vesicle. It is in close contact with the germinal vesicle and 

 is indented at the point of contact, so that it, together with the spherical 

 germinal vesicle, forms an oval area in the center of the young egg, 

 surrounded by a layer of less granular protoplasm of about equal thick- 

 ness (Plate VII, Fig. 97, 'p. z.). 



Cytoplasmic Areas. — As this outer protoplasmic layer is distinguish- 

 able throughout the later history of the egg, and must be referred to fre- 

 quently, I deem it best to give it a name, and shall call it the peripheral 

 zone (Plate YII, Figs. 97 and 88, p. z.). The outer portion of this 

 zone is further differentiated into a thin layer immediately under the 

 egg-membrane. I shall call this the subcuticular layer (Plate VII, Fig, 

 85, s. c. I.). 



The line separating the peripheral zone from the germinal vesicle and 

 sphere, taken as a whole, I shall call the cytocoel (Plate VII, Fig. 97, 



