Revieivs



29



being of a brilliant metallic copper colour with purple and violet

reflections, while the under-surface from the chest downwards is pure

white. The typical form Pholidauges leucogaster occurs in West as well

as in North-east Africa, while P. 1. verreauxi, whmh differs in having

white on the outer tail-feathers, is confined to South Africa, and a third

form, P. sharpei, occurs in East Africa.


Sexing Birds. —I think there is a great deal in the theory put

forward by Miss Knobel as to the distance apart of the pelvic bones

in the sexes of birds. It is well known amongst poultry-keepers that

these bones are considerably farther apart in a bird that is in laying

condition than in one that is not laying, in fact, hens and pullets are

constantly examined to ascertain if they are laying or not. At the

Zoological Gardens a few hens are kept as foster-mothers for young

Pheasants, etc., and during last year a fair number of young Silkies

were reared for this purpose; there are three cockerels and a number of

pullets, and I have examined these. I find that in the cocks the two

bones are barely half an inch apart, this dimension being exceeded

by all of the pullets. Some of the latter have commenced to lay, and

these have the pelvic bones more than an inch apart; in one case

the distance was an inch and three-qaurters, while in those birds that

had not commenced to lay the distance was about three-quarters of

an inch.


D. S.-S.



REVIEWS


The Auk. Yol. XXXVIII, No. 1. 1921.


This number of the organ of the American Ornithologists’ Union

opens with an interesting account of the habits of the Dickcissel (Spiza

americana), otherwise popularly known as the “ Little Meadowlark”,

or Black-throated Bunting, of the prairies of Illinois, by Dr. Alfred 0.

Gross. This first instalmant deals with the geographical range of the

species, its distribution in Illinois and its migrations, its sexual and

seasonal coloration, measurements, etc., its general behaviour and song.

The paper is illustrated with four photographic plates, three of which

show nests in situ with eggs or nestlings.



