218 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1936 



at last, some theory would be found that would explain everything. 

 That is a vain hope. There are many factors in evolution, and 

 natural selection is one of them; environment is another. But the 

 case for environment seems to require revision. At present the term 

 is too vague, and I venture to hold that many structural peculiarities 

 of plants and animals have wrongly been attributed to "environ- 

 mental influences." Perhaps the most plausible examples of these 

 "influences" are those furnished by the deep-sea fishes. 



But before I go further let me endeavor to make my meaning 

 clear on this theme. What is "environment"? Wliat do we mean 

 by the term? If we are to form any lielpful conception of what 

 is implied thereby we must go back to the primeval conditions of the 

 world, before the advent of life on its surface. 



Wlien the process of cooling began that surface was already irreg- 

 ular, broken up by deep valleys and deeper basins. With the ad- 

 vent of "rain" the water was gathered up in the valleys to form 

 rivers. And as they ran down into the basins, eventually filling them 

 to become "seas", they carried down, in solution, various salts derived 

 from the disintegration of the rocks over which they passed. Hence 

 the saltness of the sea. 



Then came the formation of "colloids", and the origin of "life", 

 which started probably in the shallower waters of the sea. This 

 "colloid" substance, being unstable in its qualities, began to assume 

 different forms of primeval plantlike organisms which gradually 

 extended their range seaward and landward, and ever assuming new 

 forms, in accordance with the nature of their assimilative powers, 

 "selecting" diflferent ingredients of the "soil" formed by this disin- 

 tegration of the rocks just referred to. 



The dawn of animal life, dependent for its sustenance on organic 

 food material furnished by these primeval plants, started later, and 

 developed, like the plants, in accordance with its assimilative and 

 selective powers, which were ever extending. Both these types of 

 living matter began with, and maintained, an inherently increasing 

 complexity of structure, evolving "individuals" more and more com- 

 mitted to a definite line of development, in accordance with the na- 

 ture of the substances taken in as "food", and the nature and quali- 

 ties of the materials fashioned from it as the result of the metabolism 

 of these several individuals. 



Here we might speak of two "environments", water and land. 

 But is there any evidence that these living bodies, still of the simplest 

 types, were fashioned by the "environment"? Already, it is true, 

 some had advanced so far in one direction as to be unable to live out 

 of the water, while some were similarly unable to live in the water. 

 But the several groups of individuals thus come into being did not 

 owe their several peculiarities, whereby they could be distinguished 



