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.” * | 
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 indi- 
cations 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.” f 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 
* ¢ Lake Ngami,’ p. 187. 
+ ‘Angola,’ vol. 11. p. 75, 
