82 Psychological Distinctions 



on which were several black feathers intermingled with the 

 ordinary ash colour on the back.* nli oi noiteltn ni bsainfi^'io 



The agency of the human race has been likened to that of 

 brutes, in the particular that, as man effects the destruction 

 of one species, he necessarily advances the interests of another, f 

 How far he may permanently benefit the latter, might be dis- 

 cussed on principles that have been already expounded. More 

 able writers, however, have put the enquiry whether man, by 

 taking certain plants, for instance, under his protection, and 

 greatly extending their natural range by cultivation, does not 

 thereby unintentionally promote the welfare of the various 

 species which subsist upon them. But, will it be argued that 

 man, by vastly increasing the breed of sheep, is unconsciously 

 labouring for the advantage of the wolves ? As little can it 

 be concluded, regarding the human race as progressive (in 

 which it differs from all other species), that any race hostile 

 to man's interests can be permanently benefited by his agency. 

 The question, in short, resolves itself into one of time. 



It has already been intimated, that man is the only species 

 that habitually destroys for other purposes than those of food. 

 This leads me to a few remarks on the extinction of species. 

 Without alluding, however, to the more direct agency of the 

 human race, towards accomplishing the destruction of every 

 terrene species which conduces not in some way to our en- 

 joyment, we will merely consider the natural causes which 

 suffice to extirpate all other races, but are inadequate to effect 

 the extinction of the human species. We have already seen 

 that brute animals, in a state of nature, are merely beings of 

 locality, whose agency tends to perpetuate the surrounding 

 system of which they are members. It tends to do so, but is 

 insufficient to effect this permanently ; because, in the immen- 

 sity of time important changes are brought about in every 

 locality, by causes ever in operation, to which the faculties of 

 the inferior animals are blind. They must, therefore, perish 

 with their locality, unless distributed beyond the influence of 

 the change ; for their adaptations unfit them to contend for ex- 

 istence with the more legitimate habitants of diverse haunts, in 

 proportion as they were suited to their former abode : and it 



* A friend informs me that he has repeatedly noticed, in Aberdeenshire, 

 the pairing of a black crow with an ordinary individual of C. Cornix ; and 

 he further assures me that, to judge from its most commonly sitting, 

 the former was in every instance the female bird. (Are not the black in- 

 dividuals noticed in Ireland, and assumed to be C. Corone, in reality varieties 

 of C. Cornix ?) It may be added, that the circumstances occasioning the 

 alleged union, stated by Temminck, betwixt the Motacilla lugubris and 

 M. alba require much additional investigation. 



t Vide IX. p. 613. 



