CLOTHING 01' ANIMALS. 21 



animals becomes lighter coloured in old age, and that the 

 human hair turns grey. Young animals seldom present 

 the same dress and vivid colours, &c. which they assume 

 upon arriving at maturity *. 



The change of colour which takes place in the dress of 

 some animals during winter, is supposed to serve other 

 purposes than the regulation of their temperature. The 

 white garb which they assume, assimilates them to the 

 colour of the snow, and in this way they are considered as 

 better able to escape the observation of their foes. 



All our conclusions concerning final causes, ought to be 

 the result of very extended observations, lest we delineate 

 arrangements which would be productive of pain and ruin 

 to many species, where we intended to unfold the marks 

 of wisdom and benevolence. If the white dress of the al- 

 pine hare and ptarmigan concealed them from their ene- 

 mies, the eagle, the cat, and the fox, these last, by being 

 deprived of their ordinary food, would be in danger of 

 starvation and death. But this variation of colour is not 

 confined to weak or defenceless animals. Beasts and 

 birds of prey are likewise subject to the change. Hence, 

 if it yielded protection to some, it would enable others to 

 prey with greater certainty of success on their defenceless 

 neighbours. Many of these rapacious animals, (as the er- 

 mine for example, which is at all times well qualified to 

 provide for its wants by its determined boldness, extreme 

 agility, and exquisite smell), do not stand in need of such 

 assistance. If this change extends to the rapacious as well 



* Young guils and solan geese, however, present very obvious excep- 

 tions. Their darkest colours are those of immaturity. Yellow seems a pre- 

 dominant tint of infancy. The hoofs of quadrupeds, and the beaks of birds, 

 are usually more or less tinged with this colour at birth. 



