Dr. Hamilton on the Plumage of the Pheasant. 485 
male, and says, “I found the parts of generation to be truly female, 
they being as perfect as any hen-pheasant that is not in the least 
prepared for laying eggs, and having both the ovary and oviduct.” 
He says, *‘ From what has been related of these birds we may con- 
clude that this change is one of the effects of age, and obtains to a 
certain degree in every class of animals. We find something similar 
taking place even in the human species; for that increase of hair 
observable on the faces of many women advanced in life is an ap- 
proach towards the beard, which is one of the most distinguishing 
Oe lag of man. Thus we see sexes, which at an early period had 
ittle to distinguish them from each other, acquiring about the time 
of ey secondary properties which clearly characterize the male 
and female,—the male at this time receding from the female, and 
assuming the secondary properties of the sex. The female at a much 
later time of life, when the powers of propagation cease, loses many 
of her peculiar properties, and may be said, except from mere struc- 
ture of parts, to be of no sex, even receding from the original cha- 
racter of the animal, and approaching in appearance towards the male.” 
In the years 1858, 1859, and 1860 this peculiar alteration of 
structure in the female organs of generation in the Pheasants was 
particularly prevalent in some parts of England. I had the oppor- 
tunity of examining many specimens, and was able completely to 
confirm Mr. Yarrell’s views on this subject. Indeed, the majority 
of the birds were young females, many. of them being birds of the 
year, some being in their first moult. I found also that the plumage 
varied and approached that of the male, not in accordance with the 
age of the bird, but with the amount of disease of the generative 
organs. The greater the destruction of the ovarium and oviduct, 
the nearer the plumage similated to the male. 
For example, in birds with the hen-plumage predominating, the 
ovarium and oviduct exist as in the fecundating hen, the small ova 
lying in considerable numbers in the ovarium, the ovarium and ovi- 
ie showing dark lead-coloured masses of disease. 
In birds with the plumage of the male in a measure exceeding that 
of the female, the ovarium is considerably diminished in size, dark- 
coloured, and containing only a few blackened ova; the oviduct is 
spotted with dark patches, and considerably contracted. 
And thirdly, in birds with the male plumage predominating over 
that of the female, the ovarium is reduced to asmall dark amorphous 
mass, resembling coagulated blood; the presence of ova cannot be 
detected, and the oviduct is almost entirely obliterated at its junction 
with the ovarium. Thus it seems that there are three distinct phases 
in this peculiar abnormal state of the generative functions. 
I have also noticed that, in most cases where the male plumage is 
in excess of the female, the tail-feathers are particularly long, some 
being as much as 19 inches in length. 
_ Although Mr. Yarrell states that this condition of the female 
generative organs is not confined to the Phasianide, and that it has 
occurred in tle gold and silver pheasants, partridges, pea-fowl, com- 
mon fowl, common pigeon, king-fisher, and common duck, and that 
Amn, & Mag. N. Hist. Ser. 3. Vol. ix. 
