xxxii INTRODUCTION 



plumage, but this change is confined to the feathers 

 of the head and neck. 



While some birds put on a new and brightly 

 coloured dress in spring, others brighten up their 

 plumage quite as conspicuously by simply shedding 

 the tips of the feathers assumed at the autumn moult. 

 No better instance of this can be found than that of 

 the Linnet, which, by this shedding process, gains the 

 beautiful rich brown back, and rose-pink breast, that 

 make these birds so much prized. For some as yet 

 unexplained reason, however, captive birds, if taken 

 in July, before the autumn moult, develop yellow in 

 the place of red — ^which colour is never regained; if 

 taken in the autumn, the red breast appears ih the 

 following spring, but never again. The beautiful 

 plumage of the Starling is similarly attained by this 

 method of shedding the outer edges of the feathers, 

 and the Chaffinch gains its blue head in the spring by 

 this same process. 



Whether birds can gain an access of colour to the 

 feathers without a moult is still a disputed point. 

 Some hold that there can be no doubt about the mat- 

 ter; while others, apparently as well qualified to speak 

 on the subject, deny the possibility of such a change 

 absolutely. 



That the colour of feathers can be influenced by 

 feeding is a fact too well known to need further com- 

 ment; but it may be interesting to remark that this 

 fact is well known to the savage people of Brazil, who 

 feed a species of green Parrot on the fat of Siluroid 

 fishes ; the feathers, as a consequence, becoming beau- 

 tifully variegated with red and yellow. Another race 



