The black on the lower parts is peculiar to the breeding season; and after the autumnal moult, they become of a light greyish colour, spotted and streaked with deep grey. In other respects the plumage is similar to that described above.
Length to end of tail 10 3/4, to end of claws 11 7/8; extent of wings 22 5/8. Weight 4 1/2 oz.
Light coloured variety. Plate CCC. Fig. 3.
Bill and feet greyish-blue. Iris deep brown. Upper part of head and back mottled with black and pale yellow; wing-coverts greyish, with white and dusky spots, as are the sides of the head and the throat; a broad band of white over the eye; fore part of neck pale grey, fading into pale cream colour and white; the breast and fore-neck with large spots of black.
This individual was killed in the breeding season.
REMARKS ON THE FORM OF THE TOES OF BIRDS.
Although naturalists have laboured, more especially since the time of the great Linnæus, who gave an impulse to the study of natural history unparalleled in that of any other science, to make us acquainted with animals of every class; and although much has been done by them in ornithology in particular, it requires little knowledge to be enabled to say with truth that a great deal more remains to be done. To take an apparently trivial example, let us look to the tips of the toes of birds, and we shall no doubt find much that is curious, and much that has been entirely overlooked. The examination of those parts was suggested to me by the following occurrence.
On the 21st of March 1816, while I was residing at Henderson in Kentucky, great flocks of Golden Plovers happening to be passing from their winter toward their summer haunts, I procured a good number of them. While engaged in drawing a fine specimen, I observed something beneath the claws, which induced me to look more particularly to that part of the toes, when I found there what might be called a second but smaller claw, equally horny with the part properly so called. I examined several others, and, finding them all alike in this respect, I mentioned the circumstance to a friend, who agreed with me in thinking it very curious. Since that period I have generally, on procuring a bird of any kind, looked to its toes, and I have found many species, both of the genus Charadrius and of other Grallæ, similarly supplied with double claws.
Although I use this term, however, let it not be supposed that I consider the parts in question as really subsidiary or secondary claws; for as they are not furnished with a central bone, or process either from the last phalanx or that next to it, they cannot be truly considered as such, however much they may sometimes resemble them.
But, in order to explain to you what I mean, let us take a general view of the subject. If we examine the foot of any common land bird, a domestic fowl for example, we observe that the extremity of its toes under the nail are rounded, and covered with quincuncial papillæ, generally flattened. The extreme degree of this rounded form is seen in the Eagles and Hawks, of which the end of the toe projects beneath the claw, having the appearance of a large round knob or rather pad. It is not, however, my intention at present to describe the structure of this part in the land birds. I may however remark, that in them, as well as in the others, the examination of the parts in question will materially aid in limiting the number of merely nominal species, by disclosing an identity of form, as well as in separating species that have been confounded, by shewing a diversity, as I have had occasion to observe, in several species of both kinds.