External Factors and Size 



133 



tremendous reduction of body size. In ten days, body 

 length diminished from 100 micra to 25, and breadth 

 from 33 micra to 12; so that about 97 percent of the 

 original body volume was lost. 



Mass cultures of single clones of Colpidium colpoda 

 were studied with respect to size by Vieweger ('25). 



2 4 6 



Time in days 



Figure 40. Effect of total starvation upon the body volume of Colpidium 

 colpoda at 20°C. The progressions in three different cultures are repre- 

 sented. (Data of Vieweger, '25). 



When a large population had formed, the organisms 

 were transferred to boiled water, and this water was 

 renewed daily. Within the first two days (figure 40) 

 tremendous reductions of body volume occurred, and 

 within a week the organisms averaged only one-fif- 



