92 GEORGE T. HARGITT 



small part to play in the activities of the cell, and the increased 

 amount of chromatin thereby present in the reticulum renders 

 the latter more obvious. 



During the growth of the egg the nucleolus increases enor- 

 mously in size (fig. 7) though this may be only apparent and due 

 to its vacuolation, but toward the end of the growth period of the 

 egg, the nucleolus decreases in size and finally disappears within 

 the nucleus. I did not find any evidence of bodily migration of 

 the nucleolus into the cytoplasm such as was described by Harm 

 and Hargitt. 



During this same period the chromatin begins to form 

 strands (figs. 8 and 9) which condense to produce the chro- 

 mosomes of the maturation spindle (figs. 10 and 11). Two 

 polar bodies are formed by mitosis as Beck with shows. In the 

 eggs which show the formation of the polar bodies I found in 

 each case 12 chromosomes, which represents the reduced number. 

 Beckwith in her figures of the maturation spindles of Clava 

 shows 10 chromosomes, but it is not indicated whether this 

 is meant to indicate accurately the entire number. I have 

 carefully examined both maturation spindles and polar bodies, 

 and where ever a count is possible, 12 is the invariable number 

 (figs. 10 and 11 b). The spermatozoon enters the egg of Clava 

 before the maturation has been completed, but the exact time 

 and the place where it enters were not determined. Figure 

 11 a is an oblique section of the second maturation spindle (the 

 chromosomes not all present in this section) and 11 b (another 

 section of the same egg) shows the first polar body and the sperm 

 nucleus as a vesicular body close to the surface of the egg near 

 the polar body. The stages of the conjugation of the nuclei 

 and the cleavage of the egg were not followed. 



