322 Recently published Ornithological Works. [Ibis, 
that full knowledge of the habits which was so conspicuous 
in Mr. Coward's treatment of such groups as the Warblers. 
But the coloration of the eggs leaves much to be desired, 
and in the case of certain of the Ducks is absolutely mis¬ 
leading : for instance, the Gadwall's egg is cream-coloured, 
not green. The reproductions of Lord Lilford's plates are 
wonderful for a book of this price; the black plates are 
good, but somewhat ordinary, while only the publisher'can 
tell whether they are necessary to the sale of the volumes. 
We should have omitted them and used them elsewhere. 
Howard on Territory in Bird Life. 
[Territory in Bird Life. By H. Eliot Howard. Pp. xiv+308; 11 
photogravures by Lodge and Gronvold. London (John Murray), 1920. 
8vo. 21s. net.] 
As a result of long-continued observation in the field on 
the breeding-habits of British Warblers, Mr. H. Eliot 
Howard has gradually come to realize the immense im¬ 
portance of the possession of territory to the male, and its 
influence on his life and actions. In the present attractive 
and thoughtful little work he has extended his studies to 
other families, and finds that the same general principles 
hold good. 
It is obvious that no species can breed unless it has 
undisputed possession of a nesting-site of some kind, 
however restricted, and to this extent every bird requires 
what we may agree to call territory. But among the 
Warblers the term includes, not merely the nesting-place, 
but a more or less extensive reserve, which serves as a 
station from which the song is uttered to attract a m&te, 
and the hunting-ground or source of food-supply, the limits 
of which are rarely transgressed by the parents during 
the whole period of reproduction. On the other hand, 
among the Auks we find the Guillemot occupying, to use 
Mr. Howard's words, (i a few square feet of rock only " for 
breeding-purposes. On the pinnacles at the Fame Islands 
it would be more correct to say that the breeding space 
