l62 POULTRY DISEASES AND THEIR TREATMENT. 



years ago, written by Hamilton (Proc. Zool. Soc, London, 1862, 

 p. 24) is of interest : "In the years 1858, 1859, and i860 this 

 peculiar alteration of structure in the female organs of genera- 

 tion in the Pheasants was particularly prevalent in some parts 

 of England. I had the opportunity of examining many speci- 

 mens, 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 tTie 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, or- 

 gans. The greater the destruction of the ovarium and oviduct, 

 the nearer the plumage assimilated that of 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 oviduct showing dark lead-coloured masses of dis- 

 ease." 



"In birds with the plumage of the male in a measure exceed- 

 ing 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 a small dark 

 amorphous mass, resembling the coagulated blood, the presence 

 of ova cannot be detected, and the oviduct is almost entirely ob- 

 literated at its junction with the ovarium. Thus it seems that 

 there are 3 distinct phases in this peculiar abnormal state of the 

 generative functions." 



"I have also noticed that, in most cases where the male plum- 

 age 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 Phasianidae, and that it 

 has occurred in the gold and silver pheasants, partridges, pea- 

 fowls, common-fowl, common pigeon, king-fisher, and common 

 duck, and that other classes of animals are liable to an influence 

 similar in kind, particularly among insects and Crustacea, yet 

 this disorganization is rarely observed except among the Phasi- 

 anidae, and particularly when these birds are produced in a do- 



