The Life-History of Hypotrichous Infusoria. 603 



Dec. Jan. Februar7 March 



1902 1903 



Diagram VII. 



April 



Sections of the culture-curves of Oxytricha A, and B, and Pieurotricba A, and B, together with 

 the temperature curve for the same period (December lo, 1902 to May 9, 1903), showing the corre- 

 spondence of the "rhythms" of the division-rate with the fluctuations in temperature. 



