16 



LORANDE LOSS WOODRUFF 



V. NUCLEO-CYTOPLASMIC RELATION 



In order to determine, whether there is any characteristic 

 change in the nucleo-cytoplasmic relation as the power of repro- 

 duction wanes, it was important to measure the volume of cyto- 

 plasm and nucleus. Here, for reasons already noted, it was nec- 

 essary to confine the study to specimens from parts B and C, 

 but results from these cells should adequately answer the ques- 

 tion. For this purpose 100 cells from B and 100 cells from C 

 were measured. In B the 244 available cells were distributed 

 through ten-day periods, nos. 29, 30, 32, 33 and 34; and in C the 

 186 available cells were from ten-day periods no. 36 through no. 

 42 (fig. 1). The 100 cells in B and the 100 cells in C which were 

 measured were taken proportionately from each of the ten-day 

 periods on the basis of the total number available in each of 

 these periods. The actual cells measured were taken at random 

 and the data secured therefore should be entirely representative 

 of the groups measured for areas and already described. 



The data secured in regard to the volume of cytoplasm and 

 nucleus are presented in tables 4 and 5, from which it is apparent 

 that, although there is great variation in cell and nuclear size 

 during each period, the mean volume of the cytoplasm and also 

 the mean volume of the nucleus is smaller in period B, during 

 which the division rate was higher, than in period C in which 



