xxi 



plumage has made its disappearance, and the male has received a garb 

 like that of the female, though of a somewhat darker tint. In the 

 early part of August this new plumage begins to change gradually, and 

 by the 10th of October the drake will appear again in all his rich 

 magnificence of dress, than which scarcely anything throughout the 

 whole wild field of nature can be seen more lovely or better arranged 

 to charm the eye of man.'** 



Mr. Waterton speaks of this change of colour as a " double annual 

 moulting," but I have grave doubts whether each change is a moulting, 

 in the common acceptation of the term ; and in years long bygone I 

 have made many attempts to invite the attention of naturalists to this 

 most interesting question. In March and April the drake has the 

 distinguishing plumage of his sex ; in June, July and August he wears 

 the plumage of the duck ; in October, November and December he is 

 again arrayed in his own beautiful livery. Now the questions to be 

 solved are these. First. Are the feathers worn in March and April 

 actually different feathers from those worn in June and July? 

 Secondly. Are the feathers worn in June and July actually different 

 feathers from those worn in October ? If so, then is Mr. Waterton right 

 | in calling it a "double annual moulting." But another suggestion 

 has been made, and is partially supported by some observations of my 

 own, namely, that the individual feathers, still remaining in situ, 

 undergo a change in colour. This inquiry is by no means to be 

 confined to the drake : gulls, plovers, linnets, and very many other 

 birds, undergo a double change somewhat similar, but the change in 

 different species is not synchronous ; thus in several species the 

 brilliant or nuptial plumage is assumed in spring; in others, of which 

 the drake is the familiar example, late in the autumn. I must 

 acknowledge the service done to Science by the entomologist, in 

 preserving a series of varieties, although not with the intention of 

 using them for educational purposes : would that the ornithologist 

 would do the same ! would that he would condescend to show us 

 those progressive changes in colour which have their meaning and 

 their teaching. Let him affix to each specimen the date when it was 

 killed : he might also indicate his own opinion as to age or sex, as 

 " ? male," " ? bird of the year," " ? adult." The date would be an 

 incontrovertible fact, and therefore always of the highest value. 

 The owner's opinion of the sex and age would often be valuable; in 

 the instance of a Doubleday, a Gould, a Hewitson, a Bond and a few 



Watertorvs 4 Essays on Natural History,' 1st series, p. 201 



