Feathers 25 



by true feathers, which overlap, protecting the body from 

 heat and cold, dust and rain. 



Fig. 12?).^Last stages in the fonnation of a down feather, showing the plumes 

 well above the surface of the skin, as in a newly hatched chick. All greatly 

 enlarged. 



At the time of the first moult, this succession of 

 feathers can be observed in almost any young bird, being 

 more noticeable in large species, which have very thick 



