ADAPTATION 



BY 



CARL H. EIGENMANN 



I. DEFINITIONS 



The chief object in the life of any animal is 

 to leave another like it in its place when it dies. 

 To this end we find numerous adjustments and 

 compromises, adaptations in animals or plants, 

 to place them in harmony with the elements of 

 their physical or biological environment, or to 

 coordinate the different parts of the same animal 

 or plant. 



We have major adaptations, such as those of 

 birds, mammals, etc., for aerial respiration, and 

 those of fishes for aquatic. We have also minor 

 adaptations for a particular combination of tem- 

 perature, light, heat, and the other elements of 

 the physical environment. And, finally, we have 

 adaptations fitting the animal to cope with other 

 animals for a mate and a home, to secure food 

 and to avoid being food. 



Aside from adaptations an organism consists 

 of vestiges, and frequently of other characters, 

 that are not adaptations. 



Vestiges, we know, are the remnants of past 

 adaptations. Specific characters which are not 



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