STUDIES IN THE PHYSIOLOGY OF SPERMATOZOA. 



199 



TABLE XL 



THE EFFECT OF THE CARBON DIOXIDE TENSION UPON THE LENGTH OF LIFE OF 



SPERMATOZOA. 



Experiment 225. 



Experiment 212. 



Experiment 213. 



For as the carbon dioxide concentration of sea water increases, 

 so also does the concentration of carbonic acid and of hydrogen 

 ions. In several experiments the length of life of a sperm sus- 

 pension at different carbon dioxide tensions 2 was determined 

 and sperm were found to live for the longest time when the car- 

 bon dioxide tension was about one millimeter. The hydrogen 

 potential of sea water at a carbon dioxide tension of one milli- 



1 In this experiment five drops of eggs were added to the undiluted suspensions. 



2 The relation between the tension and the concentration of carbon dioxide is 

 discussed on page 172. 



