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differences in the skulls of the parrots, until Mr. Abrahams told

me I was looking at the wrong part of the skull; then, turning

my attention to the lower jaw I saw it at a glance :—the posterior

angle of the two rami of the lower jaw, was elongated and acute

in the females, but comparatively short and rounded in the males.

Thus, by taking a parrot in his hand, or even by stroking the

side of the head, so as to enable him to feel the back of the jaw,

Mr. Abrahams at once decided the sex.


A character like the above should certainly be studied,

confirmed, or (if not invariably constant) disproved, by the

student of dead parrots ; to whom it might prove invaluable.


Curiously enough, I was speaking this year to Baron von

Plesson (a great admirer of the Psittacidce) respecting the sexual

differences in the Grey Parrot, and he assured me that in

Germany they always sexed this bird without difficulty by the

form of the naked patch on the face which, in the males, was

rounded behind, but in the females pointed. If this is so, it is a

curious instance of correlation in form, without any apparent

object, between a naked patch on the skin and the bones of the

lower jaw.


That the bite of a female parrot is often (if not always)

more severe than that of a male, will I think be admitted by

those who have had much to do with handling them ; and that

this is not necessarily due to the more pointed upper mandible

will be clear, if it can be shown that the jaw of the female offers

a better surface for the attachment of muscle.


In studying the sexual differences in the form of the beak,

the age of the bird must be taken into account. Thus, if it be a

general rule (as I believe it is) that males of the Thrush family

( Tw'didte ) have a longer and narrower bill than the females, one

must not conclude that this character will hold good in birds of

the year ; because even though (as in the case of the American

Blue-bird, Sialia sialis) the young bird acquires its adult colour¬

ing in the year of its birth, the nestling character of the bill does

not attain to its adult form until the bird is fully a year old. I

believe it is this fact which has caused the cabinet-ornithologist

to disbelieve in the constancy of the sexual characters which the

aviculturist accepts.


To assert the inconstancy of a character is dangerous;

because it may lead the sceptic into trouble. A bird of the year

may be, and I believe usually is in the Thrushes, smaller than its

parents. I examined all the broad-billed males of Sialia sialis

pi the British Museum series, and found them pretty uniform in



