86 THE DISEASES OF PHEASANTS. 



upon the future prevalence of tlie 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 hare sustained any 

 injury. Decomposition having set in, the young embryos will sooner or later 

 escape, migrate in the soU 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 be 

 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 {^uplocamus 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 {Tha/wmalea picta) 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 eyeKds 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 



