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JULIA ELEANOR MOODY 



cells selected during a ten-day period in May when the division- 

 rate had fallen to 1.3 for this interval. If the division energy 

 be an index of protoplasmic vitality, the cultures in May must 

 have been in a less healthy condition than in March. From 

 May to the death of the series, there was a general decrease in 

 division-rate, averaging but 0.4 during the last ten-day interval 

 in July. Reference to table 4 shows that in May, when the 

 division energy was low and the cultures had already entered 

 on a period of depression, both the coefficient and kernplasma 

 relation indicate a decrease in nuclear volume, rather than the 

 abnormal nuclear growth claimed by Popoff in his paper of 1908. 



Division rate in March = 3.1 

 Division rate in May = 1.3 



Hertwig maintained that an increase in nuclear mass led to a 

 slowing of the division rate. Table 4 shows that this is not 

 true of Spathidium, where a slow division-rate is coincident 

 with a decrease of nuclear material. 



A careful study and comparison of the nucleus plasma-relation 

 of individual cells shows a wide variation at all periods of the 

 hfe-history; for example, the measurements of one cell, fixed 

 during March, when the division-rate for the period was 3.1, 

 give a kernplasma-ratio of 1:230 in favor of the protoplasm, 

 also the average of ratios during a period of low division energy 



