Page:Popular Science Monthly Volume 8.djvu/683

Rh locality of their nests. The Rev. Mr. Eaton, naturalist to the English party, kindly gave me an egg which he had found on the day of our breaking up camp, January 10th, it being one of a nest of three, and evidently very fresh. It is a large egg, rather less than a hen's, pointed like a Guinea-fowl's, and marked by streaks and blotches of different shades of brown, which are said to vary much in hue in different specimens.

The sheath-bill is not only "an interesting bird" to know, on account of its trustful and familiar habits, but has been something of a puzzle to ornithologists from the time of its first description, by Forster, in 1788. Up to 1841 his species, C. alba (necrophaga, Vieillot) was the only one known, and has been quite variously classified. By G. R. Gray it was placed as a member of the fifth family (Chionididœ) of the order Gallinœ, a place retained for it in the British Museum Catalogue. Bonaparte associated it with gulls and petrels, as a member of his tribe Longipennes, order Gaviœ; and De Blainville, after a careful anatomical examination, decided that its nearest affinities were with the Oyster-catchers (Hœmatopus). This last decision has been accepted as final by ornithologists in general. Mr. W. K. Parker thus refers to another relationship: "There are certain curious, thoroughly marine plovers (chionis), in which the sheathing of the upper jaw is very perfect; they thus retain a struthious character, but have it in an exaggerated condition." Were this a proper place for the discussion of osteological details, it would be easy to point out other characteristics that might show a very plausible affinity of chionis to the ostrich!

Not to go deeply into the troubled and doubtful sea of the various grounds of classification of birds, it will perhaps not be out of place to mention some of the principal groups of characteristics upon which we rely to determine the place in Nature of any particular bird. First, there are the external parts: bill, eyes, plumage, feet, legs, etc., relied upon almost entirely by the older writers, and likely to hold their own, because of their convenience, for a long time yet. Then there is the digestive system, indicating also some of the affinities based upon habit. Third, and doubtless most to be relied upon, the structure of the skeleton, particularly of the skull (Huxley) and sternum, and the variations in muscular form and attachment. Last, but by no means, in my opinion, least, the habits and behavior of the bird during life.

Considered as to externals only, we find Chionis minor with the general form of a pigeon, the beak of a crow, surmounted by a sheath declared to be a characteristic of the ostrich family, with stout, knobby, short legs and feet, four-toed like a fowl's, but bare for a little way