Rates of Growth of Individuals 



25 



breadth gives very nearly the same relative values as 

 do the actually measured areas. The volume appeared 

 to increase to at least double the original volume dur- 

 ing growth; but the length hardly changed after the 

 first thirtieth of the duration of growth. The breadth 



Time after fission in hours 



Figure 11. Growth in length, in sagittal area, and in volume, in a clone of 

 Paramecium caudatum at 24° to 26°C. At each of the ages studied volume 

 was calculated as area X breadth; it agrees closely at every point with 

 volume calculated as length X breadth squared. (Data of Mizuno, 1926). 



and the volume showed significant decreases just after 

 fission. 



Another method. Another method in addition to 

 that of timing particular individuals might be used to 

 measure the rates of growth of protista, utilizing data 



