DERMATITIS 



17 



Dr. Stuhr has contributed the following account of favus in ani- 

 Favus mals : "Favus is a contagious, vegetable-parasitic disease of the skin, 

 characterized by the formation of more or less circular, cup-shaped 

 crusts, varying in size from very small up to that of a dime. It has been 

 observed in almost every species of domestic animals. The disease is quite rare 

 among horses and cattle although dogs and cats are frequent sufferers. The 

 domestic fowl and pigeon are also susceptible. 



Of the laboratory animals, mice, rats, rabbits, and guinea pigs, harbor the 



Fig. 2. Favus and Herpes Fungus. A. Spores germinating, grown in gelatine. 

 B. Hypha breaking into segments. C. Formation of spores in chains (a) formation of 

 buds (fc) chlamydospores. D. Herpes, threads of the mycelium and formation of spores. 

 B. Oidium lactis spore with germ tubes. After Grawitz. 



disease. Young age, thin skin, and debility predispose. Favus is communicable 

 from lower animals to man and vice versa. Man frequently contracts the disease 

 from cats, the latter becoming infected from eating mice and rats. 



Etiology. Favus is caused by a vegetable parasite, (Oospora porriginis) 

 which invades the cutaneous structures, especially the epidermal portion. 

 The Achorion Schoenleinii was first discovered by Schoenlein in 1839, 



