6 LORANDE LOSS WOODRUFF 



life history of Tillina magna found the largest cells when the 

 division rate was lowest. But she noted that the nucleus may 

 or may not increase in size during periods of low activity; ''if 

 an increase does take place it is generally found that the cj^to- 

 plasmic material has increased .also and the ratio between the 

 two is the same as in the periods of high activity." Moody 

 ('12) from measurements of cells from a pedigreed culture of 

 Spathidium spathula found that: 



When the division energy was low and the culture had already en- 

 tered on a period of depression, both the coefficient and Kernplasmarela- 

 tion indicate a decrease in nuclear volume, rather than the abnormal nu- 

 clear growth claimed by Popoff in 1908. Hertwig maintained that an 

 increase in nuclear mass led to a slowing of the division rate .... 

 this is not true of Spathidium where a slow division rate is coincident 

 with a decrease of nuclear material. 



From the above-mentioned typical investigations, it is to be 

 noted that those of Maupas, Calkins and Popoff showed a de- 

 crease in the size of the cell as physiological degeneration in- 

 creased, while those of Woodruff and Gregory showed an increase 

 in the size of the cell under similar conditions. The results of 

 Calkins and Moody indicated a decrease in the size of the nucleus 

 as physiological degeneration increased; those of Gregory showed 

 no uniform increase or decrease under such conditions, while 

 those of Woodruff and Popoff clearly indicated a marked in- 

 crease in the size of the nucleus. From the standpoint of Hert- 

 wig's Kernplasmarelation theor}^: Maupas' and Popoff's results 

 are affirmative; Gregory's and Moody's are negative; while the 

 results of Calkins and of Woodruff give no data from which the 

 proportion of cytoplasmic to nuclear material can be computed. 



The present paper presents the results derived from a detailed 

 investigation of cell size, nuclear size and the nucleo-cytoplasmic 

 relation during the life of one of the pedigreed races of Oxytricha 

 fallax employed in my study pubhshed in 1905. 



I have determined to make this intensive study of cell and 

 nuclear size in this race of Oxytricha fallax for several reasons. 

 First, in response to several requests for detailed information in 

 regard to the proportion of cytoplasm to nucleus during the 



