23O O. C. GLASER. 



two widely separated lobes, one of which — the lower — has the 

 nuclear membrane equally distinct throughout its circumference. 

 This nucleus was killed in the very act of pulling apart. Other 

 nuclei such as 6, 7, 8, 9, 11 and 12, seem to be dividing by the 

 formation of a granular plate, such as is exhibited by some of 

 the nuclei in Fig. 4. Others, such as 14 and 15, the latter 

 drawn with its clearly marked cell boundaries, give no indication 

 whatever of how the separation may have taken place. The 

 groups 16, 17, 18 and 19, are extremely interesting as they 

 seem to throw light on the origin of nuclear nests. Very fre- 

 quently I have found three, four or five nuclei huddled together 

 so closely that I could make out clearly no other relation between 

 them. Often one of them is at a slightly different level from the 

 others. In the cases under consideration the history of such 

 nests may be read. A nucleus instead of dividing into two, in 

 the manner of an amoeba, simply elongates, and becomes lobed 

 in two or more widely separated regions which may or may 

 not be provided with nucleoli. These lobes later separate, and 

 the original nucleus has divided into three or more parts, ap- 

 proximately equal in size or at times quite unequal. That there is 

 nothing anomalous about this mode of division is illustrated by the 

 nuclei in the external kidneys in which one frequently finds these 

 conditions clearly exemplified (Fig. 8). In comparing the nuclei 



ABC D 



Fig. 8. Nuclei from the external kidneys where cases of multiple simultaneous 

 division are frequent. These drawings were made from entire nuclei and show that 

 the divisions are not dependent on the activities of the nucleoli, which may or may 

 not be present. 



just described with those in the disintegrating entoderm cells, it is 

 clear that, excluding 17, 18 and 19, they are very much smaller 

 in size. Furthermore, the nuclei in Fig. 7 show none of the 

 chromatin masses exhibited by the nuclei in the disintegrating 



