202 



ON THE CHANGE OF 



as I have seen in other collections, but still it illus- 

 trates the principle very well, and corroborates my 

 observation, viz. that old hen-birds die soon after they 

 have assumed the plumage of the male. My friend 

 Mr Tucker of Ashburton, Devon, a most acute ob- 

 server of the habits and economy of birds, has lately 

 made known to me another instance of a common 

 hen, besides the one described in his " Ornithologia 

 Danmoniensis," which took on the male plumage in 

 old age. These facts I mention just in the order of 

 their occurring to me. 



If I had not confined myself almost exclusively 

 to birds in this paper, I might have mentioned that 

 the coat of every young grey horse becomes of a 

 milk-white colour in advanced life. The same re- 

 mark may apply to the major part of the human 

 race ; but this change in the colour of the hair only 

 illustrates the effects of age*, and not the disposi- 

 tion of the female to resemble the male. 



Most authors have observed, that birds change 

 their plumage, as well as animals their hair, twice 

 a-year ; but no one, as far as my information goes, 



* Grief is also said to turn human hair grey at an early pe- 

 riod of life. How far grief or fright may operate upon birds 

 in confinement, and dispose them to exhibit the characteristic 

 marks of age sooner than they might do if allowed to range 

 without restraint, I am not prepared to say ; but I deem the 

 subject worth inquiring into, by those persons who are emu- 

 lous of advancing this part of our knowledge of the animal 

 economy. 



