No. 2.] THE OVARIAN EGG OF LIMULUS. 155 



easy to regard them as artifacts. Careful study of the living 

 egg reveals none of those movements of the germinal vesicle 

 and nucleolus frequently spoken of in other eggs as amoeboid. 

 The stage under consideration seems rather to be a period of 

 suspended activity on the part of the germinal vesicle, and the 

 processes extending out into the cytoplasm appear rather as 

 the expression of pressure to which the germinal vesicle is 

 being exposed owing to the increasing mass of yolk. 



This period is followed later by one of renewed activity, in 

 which the germinal vesicle again becomes filled with the usual 

 hyaline karyolymph, and assumes a more definite spherical 

 form (PI. XIII, Fig. 14). Having reached the periphery of the 

 egg, it is often comparatively large and is surrounded on all 

 sides, except that immediately in contact with the yolk, by a 

 hyaline, finely spongy protoplasm, which is comparatively free 

 from yolk granules (PI. XIII, Figs. 11, 14). The contents of 

 the germinal vesicle in such cases show, especially around the 

 periphery, a finely spongy protoplasm, in every respect resem- 

 bling that surrounding it. It is still surrounded by an appar- 

 ently well-defined membrane, and contains still a large, deeply 

 staining nucleolus. This alone shows the characteristic stain 

 of chromatin. 



The ultimate fate of the germinal vesicle appears to be that 

 its membrane disappears, the larger portion of its contents 

 becomes diffused through the spongy protoplasm. This may 

 be seen as a cap, covering perhaps half of the egg (PI. XIII, 

 Figs. II, 14). It persists as such for a considerable period, 

 until the yolk spheres, now increasing very rapidly, occupy 

 practically all the space within the egg. They gradually 

 encroach on the protoplasmic cap till it is reduced to a thin 

 protoplasmic layer immediately under the egg membrane (PI. 

 XIII, Fig. 17). 



The nucleolus having disappeared as such, the last remnant 

 of the germinal vesicle can be seen as a deeply stainable, 

 irregular, amoeboid body, lying in the yolk some little distance 

 below the egg membrane (PI. XIII, Fig. 12). The yolk 

 surrounding this has a distinct radial arrangement, and this 

 radial arrangement can be traced as parallel striae to the periph- 



