Page:The Zoologist, 4th series, vol 2 (1898).djvu/491

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ASSIMILATIVE COLOURATION.
459

clay soil, strewed with fragments of small sandstone, of a purple tint. Strange to relate, we had scarcely been ten minutes on this ground when the lower extremities of ourselves and cattle became of the same purple colour."[1]

One of the most explicit observations bearing on this phase of animal colouration has been contributed by the late Mr. J.J. Monteiro. In Angola he found that in the districts where indications of copper were found, "the 'Plantain-eaters' are also most abundant, more so than in any other part of Angola I have been in";... "the most singular circumstance connected with this bird is the fact that the gorgeous blood-red colour of its wing feathers is soluble, especially in weak solution of ammonia, and that this soluble colouring matter contains a considerable quantity of copper, to which its colour may very probably be due. My attention was first called to this extremely curious and unexpected fact by Prof. Church's paper in the 'Phil. Trans.' for 1869; and on my last voyage home from the coast, I purchased a large bunch of the red wing feathers in the market at Sierra Leone, with which my brother-in-law, Mr. Hy. Bassett, F.C.S., has verified Prof. Church's results conclusively, and has found even a larger proportion of copper in the colouring matter extracted from these feathers."[2] This colour, however, as we might surmise, was sufficiently independent of the copper to have become constant, for Mr. Monteiro kept two birds in confinement in England, during which time they moulted regularly every year, "and reproduced the splendidly coloured feathers, of the same brightness, without the possibility of getting any copper, except what might have entered into the composition of their food, which was most varied, consisting of every ripe fruit in season, cooked vegetables and roots, rice, bread, biscuits, dried fruit, &c." On the other hand, Dr. Bowdler Sharpe was informed by the late African traveller, Jules Verreaux, "that the bird often gets caught in violent showers during the rainy season, when the whole of this brilliant red colour in the wing feathers gets washed out, and the quills become pinky white, and after two or three days the colour is renewed, and the wing resumes its former

  1. 'Lake Ngami,' p. 187.
  2. 'Angola,' vol. ii. p. 75.