176 THE DOCTRINE OF DESCENT. 



either die out, or else accommodate themselves to the 

 new conditions and become acclimatized. Every accli- 

 matization is therefore an adaptation, accompanied by 

 modifications more or less perceptible. Thus, in conse- 

 quence of the varied conditions of life, there is a wide 

 divergence among races of men who, by their kindred 

 language, are of the same origin, not to mention those 

 whose relations linguistic inquiry has not yet decided. 

 How different is the idiosyncrasy of the Englishman 

 from that of the Hindoo! Physically and psychically, 

 they represent two remarkable sub-races of which the pe- 

 culiarities must be ascribed to adaptation, — in the latter, 

 to a climate which requires a vegetable diet, and, eliciting 

 neither bodily nor mental energy, favours a dreamy 

 sensuality; in the former, to a country which is in every 

 particular the opposite of the Indian original home. 

 Similarly, the annual alternation in the vital phenomena 

 of so many organisms, designated as hybernating ani- 

 mals, is a case of adaptation. It is changed the moment 

 the organism is exposed to another climate, or rather 

 acclimatization is essentially the accommodation of the 

 hybernating animals to the new climate. 



In all these examples we have the results of direct 

 adaptation, in which the power of resistance in the in- 

 dividual comes into play, as does cumulative adaptation 

 in artificial, and the survival of the fittest in natural, 

 selection. In all cases of adaptation, one or several or- 

 gans are primarily concerned, either actively or passively ; 

 and only in consequence of the resulting modifications 

 are the other organs drawn into sympathy. This may 

 be termed correlative adaptation. It might be supposed 

 that the most perspicuous examples would be afforded 



