No. 3.] THE PROTOZOA AND METAZOA. 733 



ning of nuclear activity it generally lies in that half of the 

 nucleus which is nearest the sphere, and often quite close to it. 

 I have been unable to trace it further than this, when it disap- 

 pears. At about the same time — i.e., at the beginning of 

 chromosome-formation — the nuclear membrane, lying just 

 below the sphere, shows distinct undulations or wrinkles, while 

 it is intact and uniform at all other points. These can be 

 seen only in sections, but I have found them in all sections 

 of nuclei in this stage (Figs. 32-36), while in sections of 

 nuclei in resting stages the membrane is as smooth at this 

 point as at all others. At the points where the undulations 

 appear, spaces are formed by the elevation of the membrane. 

 These spaces are, as a rule, free from the basichromatin 

 and oxychromatin of the nucleus (Figs. 32 and 33). In nu- 

 merous cases, however, two minute, deeply staining granules 

 were found in the spaces thus formed. The granules were 

 always found in pairs, and in many instances no other granules 

 could be seen (Figs. 32-34). In other cases, and, I am obliged 

 to admit, in the majority of cases, other granules were found. 

 The latter always had the appearance of chromatin, and it 

 is not surprising that chromatin granules should be found 

 here, for the nucleus at this stage is full of them. The two 

 granules in question, however, have a distinct brilliancy, or 

 luster, and usually have a definite position in relation to the 

 elevations of the membranes (Figs. 32 and 33). Fig. 34 

 represents a section where the two granules lie just outside of 

 the nuclear margin, which is distinctly indented at this point, 

 and where the nuclear membrane could scarcely be distin- 

 guished. They are not in the substance of the sphere, but 

 lie in a hyaline space between it and the nucleus. A similar 

 stage is represented in Fig. 35. In this case only two other 

 granules were visible, and these are represented on the left of 

 the figure near the membrane. They are similar in form and 

 appearance to other cytoplasmic granules found in the proto- 

 plasm of Noctiluca. Finally, in Fig. -^^S, the two granules lie 

 in the sphere just outside of the nuclear membrane and the 

 latter is rapidly assuming its regular contour. Other granules 

 are pictured in the cytoplasm and in the sphere. 



