No. 2.] THE OVARIAN EGG OF LIMULUS. l^J 



acterized by a peculiar glassy translucency. The germinal 

 vesicle also, at first a nucleus not differing perceptibly from the 

 neighboring nuclei of the follicle and epithelial cells, increases 

 in size and becomes more conspicuous by the increase of stain- 

 able substance. Part of this becomes condensed, or separated 

 off and collected into a nucleolus, which previous to this time 

 could not be observed. At this time, also, the archoplasm, 

 centrosome, or vitelline-body, is more conspicuous in the 

 cytoplasm. 



Perhaps the most conspicuous feature of the egg, as a whole, 

 in this early stage is the strong affinity of the cytoplasm and 

 germinal vesicle alike for carmine and haematoxylin stains. 

 This peculiarity becomes gradually lost after the first stage is 

 passed. Unlike the nuclei of the follicle and germinal epithelial 

 cells, as well as the nuclei of other tissue cells of the ovary, the 

 germinal vesicle cannot be made to show the green stain of the 

 Biondi-Ehrlich mixture. The loss of this property appears to 

 take place about the time when the nucleolus makes its appear- 

 ance. The germinal vesicle and cytoplasm stain deeply in 

 haematoxylin and carmine stains up to the time when the first 

 layer of the egg membrane is formed. 



In the cytoplasm, during this stage, there is an area, usually 

 close to the germinal vesicle, which does not show this affinity 

 for carmine and haematoxylin stains, but which, on the other 

 hand, has a peculiar affinity for Lyon's blue, picric acid, eosin, 

 acid fuchsin, and erythrosin. At this stage the germinal ves- 

 icle is regularly spherical, and its position is usually slightly, 

 but at times very excentric. The proportion between its size 

 and the amount of cytoplasm is perceptibly greater than it is 

 found to be in later stages. 



S^age II. — In this stage the amount of cytoplasm, as com- 

 pared with the size of the germinal vesicle, has increased. The 

 cytoplasm is surrounded by a thin layer of dense substance 

 immediately under the investing membrane. The germinal 

 vesicle, instead of being spherical as before, now shows sac-like 

 diverticula that appear like buds on its surface. The nucleolus 

 has increased proportionately in size, and shows changes that 

 are not to be observed in the previous stage. This stage as 



