Colour change without a moult.



285



missionary’s note; his were caught young, and tins may have been

the case with the others also, but even so, where were they caught ?

It could not have been at the breeding-place, for then there would

have been no need for the employment of the birds as messengers,

for the message itself could have been left by the catchers, and had a

more certain chance of meeting the eye of the proper recipient. The

whole point of the need for the birds was the remoteness of the

islanders in question and the single breeding-place which was used

by every bird for hundreds of miles round.


Like these Frigate-birds I have wandered far afield. With

them, as I have come to the end of my notes, I will end, and like

them, may I leave a message of the unbounded store of interesting

matter these ‘ Proceedings of the Zoological Society ’ contain ? My

jottings are merely scraps picked up here and there, and there is

plenty of room for further search and a goodly supply of avicultural

titbits, as well as more substantial proverfder, left for others on some

future occasion, when I am once more within touch of libraries and

books. This is written in the Gambia, far away from all such

things, and to that and to the fact that it is based on rough pencil

notes made at home and brought out with me, any errors in the

references given must be attributed. My writing is never very clear

at the best of times, and it was by no means at its best in these

notes, nor has the packing improved their legibility, or, as I should

rather say, diminished their illegibility.



COLOUR CHANGE WITHOUT A MOULT.


By Arthur G. Butler, Ph.D.


I must revert to a matter which has long interested me, and

respecting which ornithologists disagree. In Darwin’s ‘ Descent of

Man,’ second edition, p. 599, the author makes the following state¬

ment : “ Some male birds . . . become more brightly coloured


in the spring, not by vernal moult, but either by an actual change

of colour in the feathers, or by their obscurely-coloured deciduary

margins being shed.”


In the ‘ Ibis ’ for July, 1916, pp. 476-478, I described the



