394 ANNUAL REPORT SMITHSONIAN INSTITUTION, 19 31 



matter that the organism may carry on its activities with a minimum 

 of adventitious disturbance. 



The fact that the living organisms of to-day have evolved from 

 more primitive forms seems to involve the assumption that the mecha- 

 nisms which have enabled living matter to survive have done so be- 

 cause of their ability to preserve at least some of its primitive charac- 

 ters. It will be interesting, therefore, to cite evidence which has been 

 adduced in support of the hypothesis that living organisms tend to 

 retain some of the properties which they may have possessed at very 

 early stages of their evolution, no matter how complex they have 

 eventually become. 



Conjectures as to the series of reactions which may have led to the 

 appearance of organic matter out of which the first living organisms 

 were formed need not concern us. We are more concerned at the 

 moment with the conditions of environment which may have existed 

 when living forms were in the early stages of their evolution. It may 

 be mentioned, however, that investigations such as those of Moore 

 (1914) and of Baly (1927) and their coworkers have indicated the 

 possibility of the synthesis of naturally occurring organic compounds 

 from water, carbon dioxide, and inorganic salts under the influence 

 of radiant energy and in the presence of inorganic catalysts. 



No matter what the conditions may have been under which living 

 matter first arose, they were obviously favorable to its appearance. 

 Conversely, since the first living organism may be assumed to have 

 been a direct product of its environment, there can be no doubt 

 but that it was eminently well adapted to its surroundings. In the 

 meantime, the conditions surrounding the living organism have un- 

 dergone tremendous changes. As far as we know, none of the living 

 organisms of the present day can be regarded as direct products of 

 their environment. 



When the composition of one of the higher forms of animal life 

 is compared with that of its surroundings, the differences which are 

 observed are much more obvious than the resemblances. Out of some 

 80 elements around it, the organism chooses 4 from which to build 

 up about 95 parts out of every 100 of its substance. When, however, 

 certain parts of an organism are compared with certain kinds of 

 environment, a much closer correspondence can sometimes be seen, 

 and there are indications that more intimate relations may once have 

 prevailed between the two than can now be shown. 



There must have been something fundamentally essential in the 

 conditions under which life began. The enormous development of 

 complexity which has taken place in some of the living organisms 

 of the present day can be traced largely to the series of modifications 

 which seems to have had for their object, the maintenance, in the 



