. Reptiles and birds : a popular account of their various orders, with a description of the habits and economy of the most interesting . Fig. 52.—Plumule. fig- 53-—Neck covert. Fig. 54.—Tail covert. same in both sexes. The young of some species attain the adultappearance after the first moult; others take several years to acquiretheir full splendour. Birds cast their feathers at least once a year. This is calledmoulting, and usually occurs in the autumn, but sometimes both inspring and autumn. During the moulting season Birds are dull,retiring, and silent; but when they emerge from this state
. Reptiles and birds : a popular account of their various orders, with a description of the habits and economy of the most interesting . Fig. 52.—Plumule. fig- 53-—Neck covert. Fig. 54.—Tail covert. same in both sexes. The young of some species attain the adultappearance after the first moult; others take several years to acquiretheir full splendour. Birds cast their feathers at least once a year. This is calledmoulting, and usually occurs in the autumn, but sometimes both inspring and autumn. During the moulting season Birds are dull,retiring, and silent; but when they emerge from this state theyproudly display their brilliant plumage, which sometimes rivals thegayest flowers. Among the Gallinaceous Birds, and especially among the aquaticspecies, there exist over the coccyx certain receptacles which distilthe oily substance with which they lubricate their plumage. Thesereceptacles are known as the uropygial glands. On its lower surface CLA IVS. 17. is a layer of cellular tissue containing a similar fluid, which seemsto be connected with the growth of the feathers. The feet of Birds are as varied in different spe
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Keywords: ., bookcentury1800, booksubjectbirds, booksubjectreptiles, bookyear1
