188 



DISEASES OF POl'I.TRV 



site was discovered in the disease of man by Remak 

 in 1837 and more completely demonstrated by Schon- 

 lein in 1841. It was discovered as affecting cats by 

 Jacquetant in 1847, and on mice by Bennett in 1850; 

 while Gerlach, Mnllcr and Leisering each pn'jlished 

 cases of it on poultry in 1858. Saint Cyr descril^ed 



the first case of 

 favus on the dog 

 in 1868 and in 

 1869 he discov- 

 ered it on the 

 rabbit. 



S V MP TOMS. — 



Favus is a dis- 

 ease of the skin 

 which in birds 

 generally com- 

 mences upon the 

 comb, or other 

 fleshy parts of 

 the head and 

 gradually extends 

 to and affects the 

 skin of the body. 

 In rare cases it 



M;r. SZ-Sarroftcs l^iis, var. ^„//^M_; larva, ]-,egitiS UpOU the 

 n on the ventral surface; matfnified 200diam => » 



body before the 

 head is affected. The disease manifests itself by 

 small white or light gray, round or irregular spots, 

 from the size of a pinhead to that of a dime, that ex- 

 tend and increase in number, until nearly all of the 

 skin of the affected part is covered. An examination 

 of these spots shows that a thin scale or crust has 

 formed on the surface of the skin. This crust often 



F 

 see 

 eters 



