Size as Structure and Function 



placed in the body of a unicellular individual. They 

 have been made for several species where the body 

 produces contractile vacuoles, by assuming that all the 



Time in minutes 

 Figure 3. Progression of the volumes of contractile vacuoles in each of 

 three individuals of Ameba proteus. The data were obtained by measur- 

 ing the diameters of the vacuoles at successive times. (From Adolph, 

 '26). 



water which passes out of the body does so through 

 the vacuoles. It is necessary then only to measure the 

 maximal volumes and the frequency of contractions 



