ALL who are concerned with the problems raised by the coloration of animals will be interested in the announcement that two hog-deer (Cervus porcinus) have just been born at the Gardens of the Zoological Society of London. This animal, of about the size of a roe-deer, has a more or less conspicuously spotted coat in the summer, and one of a uniform brownish hue speckled with white in the winter. But the young are heavily spotted, as with our fallow and red-deer, the spots serving to form a ‘concealing’ coloration. Another coloration problem, and in a way yet more interesting, now presents itself in the sixteen flamingoes just purchased and sent to the Society's park at Whipsnade. These birds lose much of the brilliance of their pink coloration in captivity. Careful note should therefore be made of the intensity of pigmentation of the new arrivals. It has been stated that birds in the London Gardens recovered their lost brilliance when they were turned out into a paddock affording free access to a large pond, well-stocked with small crustaceans. In the gardens of the New York Zoological Society an interesting experiment was made, years ago, on the beautiful rosy flamingo (Phœnicopterus ruber) which, in successive moults during captivity, became paler and paler, and finally almost white. By mixing a harmless dye with the food the fading process was considerably lessened, while some retained their original full colour for years. What was the ‘harmless dye’, and was it continuously administered? Under the more favourable conditions at Whipsnade, perhaps these birds may breed. In this event a valuable opportunity will be furnished to mark the effect, if any, of climatic influence, and food, on the coloration in their progeny.