34 DR. C. G. SELIGMANN AND MR. S. G. SHATTOCK ON THE 
lightening of the lower breast-feathers, and the feathers of the 
abdomen are generally somewhat browner and less grey than in 
the male in full plumage. There are four perfect curl feathers 
in the tail; the wing-feathers have not been shed, and are still 
quite firm. 
September 11th, 1907.—Vertex dark, slightly glossy; only a 
few flecks of gloss on the cheeks ; the white ring round the neck, 
just beginning to show after having disappeared. The breast 1s 
in eclipse; there is a moderate flush of young eclipse feathers 
coming through. The abdomen is in eclipse. The flank-feathers 
are almost entirely eclipse, but a few are in part vermiculated. 
There are no curl feathers in the tail (text-fig. 4). 
January 24th, 1908.—Although the general appearance of this 
bird is predominantly that of a male in winter plumage, there 
are many signs that the eclipse is only slowly passing off. The 
vertex is dark, but it can scarcely be described as glossy, though 
the rest of the head is generally so, with only a few brown 
feathers remaining. The white ring, however, round the neck 
has now become well marked. There is much eclipse plumage 
left on the breast and abdomen. The flanks are in partial eclipse, 
a number of incompletely vermiculated feathers being present. 
The tail contains one poorly developed curl feather; the three 
other central feathers are dark and beginning to ridge—the first 
stage in the formation of the curl. 
(No. 2.) Bird in full winter plumage ; castrated December 20th, 
1906. The testes removed were brownish yellow, and did not 
exude fluid on section. The tubuli were full of cells, and though 
no spermatozoa were present there were abundant mitoses. 
July 11th, 1907.—Although the general appearance is that of 
a bird in winter plumage, it is modified by a considerable flecking 
with brown feathers on the sides of the face, and by the occur- 
rence in the anterior portion of the grey of the breast, of indi- 
vidual feathers of a dull black edged with brown. The vertex is 
glossy, and there are four perfect curl feathers in the tail. 
The photograph of this bird (text-fig. 5, p. 36), taken on 
September 11th, 1907, shows that the assumption of the winter 
plumage was delayed. The plumage is predominantly eclipse. 
There is no gloss on the head, and although the central tail- 
feathers are beginning to ridge, by far the greater number of the 
feathers on the head, belly, back, and shoulders exhibit wholly 
or in part the dusky coloration of the eclipse. 
September 11th, 1907.—The vertex is dark and only slightly 
glossy ; a few flecks of gloss are present upon the cheeks. There 
is no white ring on the neck. The feathers on the breast are 
predominantly eclipse, but here, and on the abdomen, there 
are feathers which are partially vermiculated, and there is an 
abundant flush of fresh vermiculated feathers coming through ; 
among them there are a few eclipse feathers. The flanks contain 
many eclipse feathers and some new vermiculated ones. There 
