522 



GROWTH 



growth of P. caudatum and some of his control series, with more fre- 

 quent measurements, are plotted. Measurements of growth in length by 

 Schmalhausen and Syngajewskaja (1925) and by Mizuno (1927) are 

 also available for P. caudatum. Mizuno also determined the area of the 

 animal with a planimeter, from a camera-lucida tracing. 



-75 



HOURS 



f^. . . I , N , I . I' , 



12 18 24 



Figure 131. Growth in breadth and thickness (TH) of Paramecium caudatum. Data: 

 P from Popoff (1909), M from Mizuno (1927), J from Jennings (1908), E21, E28, 

 and E38 from Estabrook (1910). 



All of the investigators took precautions to prevent any change in the 

 dimensions of the organism from killing the organism. The curves for 

 growth in length are quite similar. All were grown in hay infusion 

 medium and the temperature, when stated, was 24-26° C. Mizuno's ani- 

 mals grew at first at a more rapid relative rate than the others. Esta- 

 brook's and Schmalhausen's animals were appreciably larger than 

 Jennings's, Mizuno's, and Popoff's Paramecia. The decrease in the early 



