OXYGEN SUPPLY OF CERTAIN ANIMALS 309 



But it seems very probable to the writer that some relationship 

 exists between the two peculiar conditions — the presence of the 

 enzyme complex in the chironomid larvae and the absence of 

 the usual oxygen supply for a portion of each year. This seems 

 doubly probable because of the fact that the ability of the chitin 

 to oxidize guaiacum was found to be more intense in its action 

 during those times of the year when dissolved oxygen was present 

 in the lower water and gradually became weaker during the 

 continuance of the stagnation period. It would seem that 

 something was being stored when oxygen was abundant which 

 was gradually used up when oxj^gen was not available. This 

 material stored up cannot be in the form of a peroxide, because 

 in the first place peroxides are toxic to living protoplasm, and, 

 secondly, they would be broken down in the presence of the 

 peroxidase-like substance found in the larvae's body. And if 

 the stored substance is the enzyme itself, what avail would it 

 be in the production of a peroxide, when it is dependent in its 

 action on molecular oxygen which is absent during the stagna- 

 tion period? A further investigation is already in progress by 

 which the writer hopes to clear up this phase of the problem. 



It has been suggested that the oxidation of guaiacum is not a 

 sufficient index to the production of atomic oxygen, that it is 

 merely an indication of the presence of a powerful oxidizing 

 agent, which is siaiilar in its action to atomic oxygen. The 

 exact steps in the chemical reactions concerned in such an 

 oxidation are not well understood. It has been argued that a 

 peroxide may unite with the oxidizable substance, eliminating 

 water in the reaction. In such a case the substance would be 

 finally oxidized, but atomic oxygen would not necessarily be 

 formed. However, neither hydrogen peroxide nor the organic 

 peroxide found in old turpentine have any immediate effect on 

 guaiacum, but this does not prove that some other highly complex 

 organic peroxide might not have such an effect. In any event, 

 the experiments performed by the writer show that the chiro- 

 nomid larvae contain, or are capable of forming in the presence 

 of oxygen, an oxidizing substance capable of oxidizing guaiacum 

 which would probably also be capable of oxidizing substances 



