296 On the Ornithology of Wilts [3IeruliJ(e\ 



of place here ; suffice it to say, that I conceive tbat plij'sical weak- 

 ness either in the individuals themselves, or in tlieir parents, one 

 or both of them, is the radical origin of the varieties in colour so 

 often seen; and that the natural and habitual functions of tlie 

 bird are through debility so disarranged, as to have the effect of 

 withdrawing the pigment or colouring matter from the growing 

 feather, as it springs from the follicle sheath or capsule in whicli it 

 is enveloped, and where it is nourished by juices in which the pig- 

 ment is supjDosed to reside. There may be man}^ exciting causes, 

 such as peculiar food, sudden fear, extreme rage, «&c., serving to 

 develope this peculiarity in colour, or it may have existed from the 

 nest, but in all cases I apprehend that constitutional weakness is 

 the real root of the matter; and as bright well marked plumage 

 undoubtedly betokens good health and strength, so and on the same 

 principles I conceive that an unwonted variety or absence of colour 

 marks phj^sical debility : and therefore I am no admirer of these 

 anomalous specimens, but rather look upon them as miserable 

 deformities and wretched abortions, the offspring of Aveak parents, 

 unfitted to rank with their fellows. I may add that I have col- 

 lected authentic evidence of the existence of such varieties in no 

 less than fifty-seven species of our British birds, in their wild state, 

 and have no doubt that if further investigated, it would be seen 

 that such occasional deformities resulting from weakness do some- 

 times occur in every species of bird, though in those wearing the 

 darkest livery, (such as the blackbird and the rook,) and therefore 

 requiring a larger supply of pigment, such varieties will be found 

 to be more frequent. 



"Ring Ouzel" {Tiirdus torqiiatiis). Here we have another mi- 

 gratory species of thrush, but unlike its congeners, the fieldfare and 

 redwing, which come to us in the autumn and retire northwards in 

 the spring, the ring ouzel comes to us in April, and retires again 

 in October : it is however in this county but a bird of passage, 

 never remaining with us to breed, but retiring to more northern 

 districts in the summer, and more southern climes in the winter: 

 it is easily distinguished from the blackbird by the absence of the 

 bright yellow bill, and by the white collar or broad crescent-shaped 



