1)2 



can only hv produced by the siK'cilic oij^anisnis of tlic 

 disease. Jt is undoubtedly tiu(! that unfavorable in 

 tluences, svch as those that cause colds predispose 

 poultry to roup and i)lace the birds in such a condition 

 that they are more a})t to develop it when exposed to 

 it, and jteiJiaps cause tlie appearance of the disease in 

 a severe and tatal form wlien it would have followed a 

 mild course if these unfavorable conditions had not ex- 

 isted. Young fowls, tender breeds, and birds in poor 

 co-ndition, and especially thoise that are poorly cared 

 for, are most predisposed to roup. All varities of do- 

 mestic fowls may contract it. It also affects cage 

 birds and outbreaks have been described among wild 

 birds. 



The characteristic symptom from which this disease 

 derives its name consists in the appearance of wliite 

 patches (m the membrane lining the moaith and nose, 

 the air passages; and these same patches occasional! v 

 develop on the sldn, in the intestines or in the lungs. 

 The patches or roup are at first white and resemble a 

 white mould. The size of the patch is indefinite and 

 never the same in two individuals. Tt may be very 

 small, or it n.ay extend over the entire lining mem- 

 brane of the mouth. Sometimes, it appears first on 

 the sides of the tongue, sometimes on the roof of the 

 month, sometimes in the throat or about, or in. the 

 nose or eye, on the skin of the head, or in the deeper 

 ]»arts of iho body. At tii-st, the fowl does not show 

 mncli iiicoii\('iiience. As the i)atch nialuies it V»e- 

 comes yellow, its borders dry and adhere closely tt) 

 tlie mucous membrane, and if it is large enough, it 

 may obstruct the air passages oi" the mouth and cause 

 s<'rious difficulty in breathing. At this stage of the 

 disease the fowl icfuses food, becomes sluggish and 



