26



The snake theory is a favourite one with the more

enthusiastic of modern evolutionists, but I hold to the view

that the ornamentation is merely a guide to the open mouth of

the infant bird, and in this opinion I am pleased to find that I

have the support both of Mr. St. Ouintin and Mr. Meade-Waldo.


In a letter dated September 25th, Mr. St. Ouintin writes

as follows :


“ As regards the moutli-ornamentation, in a short paper

on the breeding of Parrot-finches, which I have lately sent to

Mr. Fillmer, I mentioned that the nestlings of that species bave

somewhat similar bead-like warts on the mouth (as the Gouldian

Finches).


“ I found yesterday, in a nest-box, some partly fledged

young Cordon-bleus which had died ; these also showed some

mouth decoration, but they were not fresh enough to send up to

you.


“ In that paper I suggested that the iridescent warts and

palatal spots might be of service to the parents at feeding-time,

in the case of birds breeding in covered nests or in holes. But,

on the other hand, I do not know any of the native hole-

breeders, or those with domed nests, whose nestlings have any

special growths or excrescences ; though some of them breeding-

in holes, as Tits, and also birds building in the semi-darkness of

dense bushes, as Hedge-sparrows and others, have brightly

coloured gapes, which may answer the same purpose of indi¬

cating where a hungry mouth remains to be filled.


“ Mr. Meade-Waldo, who is staying with me, has just

bred some Black-headed Gouldian Finches ; and tells me that,

in the darkness of a nest-box in the upper part of the aviary

under the roof, the six young birds could be easily counted by

the gleaming beads on the edges of their mouths, even when

nothing else was visible.”


It is asserted by certain evolutionists of the modern

school that ever) r type of ornamentation has a definite object and

is necessary to the preservation of the species, but I am not

convinced of the truth of this assumption ; for I believe that

excess of vital energy in any part of an organism may find vent

in the production of a monstrous growth, which may not be

absolutely necessary, though not injurious: or may only serve

the same purpose as a far less remarkable modification.


The swollen and expanded base of the upper mandible

in P. mirabilis (w T hen first hatched) is dull yellow, but as it



