CLOTHING OF ANIMALS. 23 



night V Staggered with the statements of such a frequent 

 renewal of the dress of animals, accompanied by such a 

 wasteful expenditure of vital energy, and guided by multi- 

 plied observations, we ventured to offer the following re- 

 marks on the subject in the Edinburgh Encyclopedia, un- 

 der the article " Hybernation," vol. xi. p. 387, published 

 in 1817. 



" It has been supposed by some, that those quadrupeds 

 which, like the alpine hare and ermine, become white in 

 winter, cast their hair twice in the course of the year ; at 

 harvest when they part with their summer dress, and in 

 spring when they throw off their winter fur. This opinion 

 does not appear to be supported by any direct observations, 

 nor is it countenanced by any analogical reasonings. If 

 we attend to the mode in which the hair on the human 

 head becomes grey as we advance in years, it will not be 

 difficult to perceive that the change is not produced by the 

 growth of new hair of a white colour, but by a change in 

 the colour of the old hair. Hence there will be found some 

 hairs pale towards the middle, and white towards the ex- 

 tremity, while the base is of a dark colour. Now, in ordi- 

 nary cases, the hair of the human head, unlike that of se- 

 veral of the inferior animals, is always dark at the base, and 

 still continues so during the change to grey ; hence we are 



* u Ornithological Dictionary," Introduction, p. 25. London, 1802^ 

 The same intelligent observer continued, even after the publication of the 

 " Supplement" to the above work, in 1813, where the subject frequently 

 came under his notice, to entertain the same opinion. He was disposed to 

 admit two, and in some cases three successive moultings in the course of a 

 year. In a letter which I received from him on the subject, dated Knowle, 

 7th December 1814," he adds, But I have no conception of a change of 

 colour in the same feather or hair, (because the colouring matter has been 

 disposed in embryo), except by length of time, as our hair is changed by 

 age;" 



