1917] Swarth-Bryant: White-fronted Goose in California 211 
blotching of the lower parts increases in extent with the passage of 
years; and the individuals occasionally encountered in which the 
lower breast and abdomen are uniformly black are thought to be 
of great age. If this idea is reasonable, and it appears to be so, 
the big birds in question cannot be regarded as being of exceptional 
age. None has the belly unusually heavily blotched, while on the 
other hand several of the smaller sized birds are almost entirely 
black below. 
Sex and age having been thus excluded as causes of the observed 
differences, it became necessary to make a careful comparison of the 
two series of specimens, the large tule goose and the small white- 
fronted goose, in order to find a more satisfactory solution of the 
question. Fortunately, enough examples of both were available to 
make this practicable. 
The difference in size between the two subspecies was equally 
noticeable whether the comparisons were made before skinning the 
specimens or in tabulated measurements. This was at once sugges- 
tive of a like contrast within the Branta canadensis group. The large 
tule goose may be compared with the Canada goose, which it closely 
approximates in bulk. The smaller white-fronted goose is comparable 
to the Hutchins goose in size, while, to complete the analogy, the 
Asiatie species, Anser erythropus, may be paralleled with the tiny 
cackling goose. A similar variation is to be found in the North 
American snow geese (Chen), there being in this genus three species 
comparable in size. 
A color distinction that is at once apparent between the two series 
of Anser is that the larger birds are of a browner tint, and the smaller 
ones more gray. This is especially noticeable on the heads and necks. 
In some individuals of the larger race the head is extremely dark 
brown, almost black. In the distinctive markings, the white face 
patch and the black blotches on the belly, there appears to be no 
difference between the two. 
In one of his communications (see below) Judge Henshaw called 
attention to the fact that the tule goose has a yellow eye-ring, a feature 
that is not present in the white-fronted goose. This important char- 
acter is not apparent in a dried skin, and it had been overlooked 
in the first few specimens that came in, but its presence was verified 
in all but one of the large geese subsequently received. This marking 
is similar to that ascribed to Anser'erythropus, the edge of the eyelid 
being naked skin, and forming a bright yellow ring about the eye. 
