86 : THE DISHASES OF PHEASANTS. 
upon the future prevalence of the disease is the total destruction of the parasites 
after their removal. If the worms be merely killed and thrown away (say upon 
the ground), it is scarcely likely that the mature eggs will have sustained any 
injury. Decomposition having set in, the young embryos will sooner or later 
escape, migrate in the soil or elsewhere, and ultimately find their way into the 
air-passages of birds in the same manner as their parents did before them. 
The worms, after removal, ought to be burnt, and the dead bodies of any 
chickens, young partridges, or other birds infested with these parasites, should he 
treated in the same manner if we wish to avoid the spread of the disease. 
Disease of the ovary attended by the assumption of male plumage by the 
female pheasant is a phenomenon that has long attracted the attention of 
naturalists. It was described by John Hunter in his “ Animal Economy,” and in 
the “Philosophical Transactions,’ vol. Ixx, p. 527, and also by the late Mr. 
Yarrell. Although gamekeepers frequently speak of the hens thus changed in attire 
under the title of mule birds, it is now perfectly well known that the assumption 
of male plumage is invariably caused by disease of the ovary, and the birds 
exhibiting this change are, without any exception, always barren and useless females, 
not, however, necessarily old birds, as the change of plumage may result from ovarian 
disease in a hen that has not laid. The change takes place to a varying extent, 
usually beginning with a slight alteration of the neck feathers. In some cases it is 
absolutely entire; the hen being clothed in perfect masculine plumage, not a single 
feather of the body remaining unchanged. This singular modification is not confined 
to the common species, but extends doubtless to the whole group. It is recorded 
as occurring in the Silver Pheasant (Euplocamus nycthemerus) in the Field of 
Nov. 13, 1869, and, thanks to the kindness of Mr. Leno, I had in my possession 
a Golden Pheasant hen (Zhawmalea wpicta) in which the metamorphosis was 
complete. Mr. Leno had had this bird in his possession for some years, and had 
noticed the alteration increasing at each annual moult. A corresponding alteration 
has been frequently observed in the female of the domestic fowl, and it is 
not even confined to gallinaceous birds, being not unfrequent in the domestic 
duck. That disease of the ovary should cause the formation of feathers totally 
distinct, not only in colour, but in form, from those previously produced, as is most 
conspicuously the case of the tippet of the Golden, or tail of the Silver, pheasant, 
is a very remarkable circumstance, and one that has not yet received a satisfactory 
physiological explanation. 
Young broods are occasionally the subject of inflammation of the eyes, an 
epidemic ophthalmia, which is exceedingly troublesome, as the eyelids become glued 
together by the adhesive discharge, and the birds perish from want of food if not 
constantly attended to. By way of treatment the dropping into the eye a few 
drops of a lotion of nitrate of silver (about three grains to the ounce of distilled 
