WILLIAM TOWNSEND PORTER 105 



imal experimentation should weigh their purpose well. A 

 great philosopher has stated clearly the inevitable conse- 

 quence. Darwin wrote in 1881 : "I know that physiology 

 can make no progress if experiments on living animals 

 are suppressed, and I have an intimate conviction that to 

 retard the progress of physiology is to commit a crime 

 against humanity." l 



1 From a letter to Pasteur dated April 14, 1881. Life of Pasteur, vol. ii., 

 p. 149. 



