No. 2.] THE OVARIAN EGG OF LIMULUS. 135 



The Egg. 



The germ cells lining the ovarian tubes of the young animal 

 when the lumen has appeared are spherical in form (PL XIV, 

 Fig. 38). The cytoplasm of the body is relatively abundant 

 in the resting state, and is comparatively free from granules. 

 The nucleus occupies approximately the center of the cell. It 

 is not relatively large, but it contains considerable chromatin, 

 which stains deeply. 



As these cells prepare for division the nucleus becomes 

 greatly enlarged, and the chromatin assumes a distinct and 

 highly characteristic network (PI. XIV, Fig. 33). Dark, 

 straight fibers are seen to intersect other straight fibers, at 

 various angles ; and these, again, can be seen to unite with 

 similar fibers at the periphery of the nucleus. Here dark, 

 bead-like chains of chromatin granules appear to constitute 

 the only boundary of the nucleus. These bead-like bodies are 

 not always evenly distributed, but considerable spaces some- 

 times appear between them. By adjusting the focus, however, 

 similar granules appear in these spaces, indicating that we 

 have here to do with a network which lies at the boundary of 

 the nucleus. At the points of intersection of the chromatin 

 rods within the nucleus there is always a considerable enlarge- 

 ment. The karyolymph is hyaline, and the chromatin 

 element does not appear to be so abundant as to make the 

 nucleus as conspicuous as it becomes in the next stage (Fig. 

 35). Now the nucleus, retaining its former size or even 

 slightly increasing, is seen to be filled with a deeply stainable 

 thread which appears to have the form of a coil and which fills 

 the nuclear space. It could not be determined whether this 

 is a single thread or several threads. Appearances seem to 

 show that there are more than one thread ; at any rate, several 

 apparently free ends could be seen at all times. Careful 

 examination of this thread shows distinctly that it consists of 

 spherical bodies arranged in single rows closely applied so that 

 in places the rod seems continuous ; but the granules are often 

 slightly separated one from the other. This, in all probability, 

 may be taken to be the preliminary phase, spireme, of karyo- 



