344 BIOLOGY 



corolla and thus reach the honey, it would not be able to utilize 

 this food. Each butterfly is provided with a tongue sufficiently 

 long to obtain the honey from the particular kind of flower 

 upon which it feeds. The marvelous structure of the human 

 hand, with its wonderful mobility, its delicate sensations, its 

 great power of muscle movement, is clearly adapted for use 

 as an organ of prehension, and one might believe, as has been 

 vigorously argued, that it was especially made by an intelli- 

 gent designer for the conditions of life in which man lives. 



The principle of adaptation is found everywhere in nature, all 

 animals and plants being more or less adapted to their conditions 

 of life. Indeed, perhaps the most characteristic feature of or- 

 ganisms is that they are adapted to their environment, instead 

 of being purely haphazard in their shape and structure. In- 

 animate objects, like stones, have no special relation to their 

 environment, and having been produced by blind forces, are 

 not particularly adapted to any purpose. In contrast to this, 

 all animals and all plants show structure and functions which 

 fit them for their environment. We may almost regard this 

 feature of adaptation as the most universal and striking char- 

 acteristic of life. 



Origin of Adaptation. How came organisms to be thus 

 adapted to their environment? The explanation of adaptation 

 which was for a long time regarded as satisfactory, was that 

 each animal was made by an intelligent Creator, and exactly 

 fitted to the environment in which it was placed. This sug- 

 gestion was satisfactory so long as it was believed that each 

 species was an independent creation. Since, however, the idea 

 of special creation has been replaced by the belief that our 

 present species have been derived from older types by descent, 

 the problem of adaptation to their environment must be given 

 a different solution. If animals have diverged from common 

 centers, it follows that types now inhabiting different localities 

 must have originally come from the same place, and if they 

 were originally adapted to one locality, they could not be 



