. Animal coloration; an account of the principal facts and theories relating to the colours and markings of animals. Animals. 96 ANIMAL COLOKATION. sluggishness of the animal, this colour may have a protective value. The colour, however, curiously enough, is purely ad- ventitious, and is the only example of the kind among the Mammalia. In captivity the sloth gradually loses this green colour, and becomes greyer ; this is not a change comparable to the gradual fading of the brilliant red of the scarlet Ibis, but is simply due to the disappearance of certain minute Alga?,. Fig. 5.—The Sloth. whi
. Animal coloration; an account of the principal facts and theories relating to the colours and markings of animals. Animals. 96 ANIMAL COLOKATION. sluggishness of the animal, this colour may have a protective value. The colour, however, curiously enough, is purely ad- ventitious, and is the only example of the kind among the Mammalia. In captivity the sloth gradually loses this green colour, and becomes greyer ; this is not a change comparable to the gradual fading of the brilliant red of the scarlet Ibis, but is simply due to the disappearance of certain minute Alga?,. Fig. 5.—The Sloth. which, as Mr. Sorby first discovered, are the cause of the peculiar coloration ; doubtless it is the absence of a damp and warm climate that is fatal to the Algas, and is the cause, therefore, of what appears to be an actual change in the colour of the hair itself. It would be difficult, therefore, to set down this case of what appears to be an adaptive coloration to the action of natural selection ; though it must be admitted that we still have to explain why this animal alone should be subject to the intrusion of the Algte: possibly its sluggish. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Beddard, Frank E. (Frank Evers), 1858-1925. London, S. Sonnenschein; New York, Macmillan
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectanimals, bookyear1892
