Catalase Content of Tissues. 131 



catalase activity rapidly increased until at the end of the seventh 

 or eighth day it was as high as that of the adult. We repeated 

 and confirmed these observations using the dog and newly-born 

 puppies. We also determined the catalase content of the tissues 

 of puppies that were about ten weeks old and found that the 

 tissues generally were richer in catalase than those of the mother. 

 The catalytic activity of the liver, for example, of the ten week 

 old puppies was about thirty per cent, greater than that of the 

 liver of the mother. The catalase was determined by adding one 

 gram of the hashed tissue to hydrogen peroxide and the amount of 

 oxygen liberated in ten minutes was taken as a measure of the 

 amount of catalase. 



Appleman 15 found that there was an increase in catalase 

 parallel with the increase in oxidation in the greening of potato 

 tubers, but that the oxidase activity was not increased and, in 

 fact, was slightly decreased. He also found that the exposure of 

 potatoes to ethyl bromide gas increased the catalase of the potato 

 parallel with the increase in oxidation, while it had no effect on 

 the oxidases. 



The low metabolism or oxidation in the newly-born is attri- 

 buted to the low catalase content of the tissues, due undoubtedly 

 to the small ouput of this enzyme from the liver, while the high 

 metabolism in youth is attributed to the richness of the tissues in 

 catalase brought about by a large output of this enzyme from the 

 liver. Likewise, the increase in oxidation or metabolism in the 

 sprouting of grain or of potatoes is attributed to an increase in 

 catalase. The increase in oxidation or metabolism and hence the 

 development of the fertilized egg is attributed to the increase in 

 catalase brought about by the stimulation of the egg by the 

 spermatazoon to an acceleration in the formation of this enzyme. 



15 Appleman, The Maryland Agricultural Experiment Station, 1915, Bull. 191. 



