1078 LIFE : OUTLINES OF GENERAL BIOLOGY 



ence. Perhaps the greatest difficulty in the face of this theory is to 

 suggest any reason for the origin of even incipient variations in the 

 direction of such extraordinary fitnesses as the withered-leaf-Hke 

 patterns on some butterflies, or the egg-opener of some larval 

 insects that serves to cut the hard chitinous egg-shell and allow 

 emergence. It is the first step that counts; and while we can under- 

 stand the increase, and elaboration of a structure by cumulative 

 variations in the same direction after it got under weigh, it puzzles 

 us often to imagine the beginning. "Some philosophers think 

 that a faculty's granted, whenever it's shown to be very much 

 wanted". 



Osborn, Morgan and other evolutionists have pointed out that 

 although individual adaptive modifications may not be transmissi- 

 ble, they may have indirect importance in evolution, by serving as 

 life-preserving screens until coincident germinal variations have 

 time to be estabUshed; and to this they have applied the term 

 "Organic Selection"' — not a very clear one. Thus an insect may be 

 protected in colour because of what it eats until in the course of 

 time it puts on cryptic colouration in some less direct way — varia- 

 tional, not modificational. As Gross puts it, in speaking of some 

 instinctive activities: Imitation may keep a species afloat until 

 Natural Selection can substitute the lifeboat of heredity for the 

 lifebelt of tradition. But the metaphor is perhaps too suggestive of 

 a shipwrecked world. 



Whatever view be taken, it must include a recognition of the too 

 frequently overlooked commonplace that organisms may share 

 actively in their own evolution. As Prof. James Ward was wont to 

 emphasise, an animal may seek out and even in part make its 

 environment; it is not only selected, it selects; it acts as well as 

 reacts. Environment acting on organism (E -» f -^ o) —sustaining, 

 stimulating, sifting — is one aspect of what we see; but the other is 

 Organism actively functioning on environment (O -> f -> e) — 

 changing, testing, choosing. The degree of this different sort of 

 "Organic Selection" varies greatly with the type; but the use that 

 an animal makes of an adaptive variation — say, the shape of its 

 body — must have its effect on the success of that variation, e.g. on 

 the rate of its racial estabhshment. 



Caution re Adaptations. — ^We have given so many instances 

 of adaptation, and of so many kinds, that it may seem we see them 

 everywhere: so a word of caution is needed; indeed, two. First, 

 that as adaptations arise in course of evolution, and as part of its 

 progress, they may often have ample room for progress and for 

 increase; and second, that adaptation is not by any means always 

 so reciprocal as it looks, but may be only one-sided. Of this, to 

 avoid criticisms which might lead us too far, and sometimes into 



