IQ'^ Le Souef, Birds Changing Colour of Plumage. [isf April 



problem not so noticeable in Australasia. Here we have no land connection 

 with Polar regions, and consecjuently the same conditions are not brought 

 prominently under the notice of observers. 



Recorded facts and probabilities both seem to favour the theory advanced 

 by Mr. Le Souef; but is there sufficient evidence to establish it as proved? 

 His examples are from birds in captivity, and the question arises as to 

 whether birds under such circumstances behave exactly as they would in a 

 wild state Certainly in the case of semi-domesticated birds, such as 

 Pheasants, one would expect them to do so. It is hard to conceive that any 

 very great change of habit could follow, so long as suitable surroundings and 

 food were provided. The specimens of feathers exhibited tend to elucidate 

 one disputed point — viz., whether the barbs and barbules, vanes, &.C., of a 

 leather are after a certain stage physiologically living or dead. Some 

 writers on the subject regard only the lower part of the shaft of a feather as 

 alive, and that as only actively alive during the earlier stages of a feather's 

 growth. If, as is to be assumed from his paper, Mr. Le Souef has 

 conclusive evidence that no feathers were shed by the Pheasants in cjuestion, 

 he will have got a step forward towards the solution of this phase of the 

 problem. His specimens apparently hved until the death of the bird. But 

 a difficulty will still remain. The exhibits are not, and could not possibly 

 be, of the same feather in different stages of development or of maturation, 

 and similar ones, though they be in similar or advancing stages of coloura- 

 tion, hardly prove the case. Is it possible that the change of colour is 

 partly produced by the shedding and replacement, or even by the 

 rearrangement of minute barbs and booklets, and of what may be called 

 "scales" — something more minute still — that is, by alteration of the angle 

 at which they are set on the surface of the feathers? The white "dust" 

 sometimes observed when handling a Cockatoo in some stages of plumage 

 is one proof of the existence of these " scales," and that they are under 

 certain conditions shed. Examination under a microscope reveals that to a 

 certain extent the colouration in Peacocks' and other feathers is an effect of 

 the particular angle at which light rays are refracted from or absorbed by 

 the minute structures with which they are covered. That some pigment 

 does exist must be allowed ; but, even what we call by that name is only 

 the particular and varied arrangement of atoms, and in an active cell these 

 might undergo rearrangement, and thus produce a different effect. And if 

 the whole feather be really alive during the full term of its retention by the 

 bird, its cells would probably be active enough to carry pigment or alter its 

 atomical arrangement. 



To prove that some birds do change colour without moulting, we have 

 Mr. Le Souefs facts, supported by, amongst other things, an instance cited 

 in The Emit (vol. i., No. 2, p. 71), in which a Galah (Cockatoo), when 

 injured, changed the hue of portion of its plumage : — " Two days after the 

 injury the pink of the injured side had turned a dark red, and the grey of the 

 back was distinctly darker on that side." But against all this — unless it be 

 assumed that birds must be divided into two classes (one which moults 

 when changing colour, and one which does not) — must be set some other 

 facts. For instance, in the Avicultural Magazine (p. 18. vol. i., new series), 

 writing of the Blue Wren {Malunis cyaiieiis)., Mr. Regd. Phillipps says : — 

 " Early in September the male commenced a full moult, and now, at the 

 beginning of October, scarcely a vestige of his old glory remains. The tiny 

 blue feathers, cast from his head and blown out of the cage by the bird's 

 wings, would lie on the carpet and on the oilcloth in front of the cage, and 

 looked like little specks of blue wash." A young bird is also mentioned as 

 moulting before assuming the adult plumage of the female. Other instances 

 might be given, but this case appears worth citing, because in this Wren 

 there is both a change from immature to mature plumage and a seasonal 

 change. Whether it be moult or change of colour that takes place in birds 

 in a wild state is hard to prove — (stray specimens, even if procured at close 

 intervals, are not fully satisfactory evidence, and the whole matter resolves 



