232 



APPLIED BACTERIOLOGY 



Bazin. In its earlier stages it is indistinguishable from 

 the Tinia tonsurans, but soon assumes the honeycomb 

 appearance. It grows on all ordinary media except milk. 

 Gelatine is liquefied. On agar the colonies appear dis- 

 tinctly in forty-eight hours ; they are surrounded by a 

 fine fringe of threads. On blood serum star -shaped 

 colonies are formed, which radiate out from the centre, 

 producing a flower-like appearance; the gelatine is not 

 liquefied. It also grows well on bread and potato. 



Favus affects man, dogs, cats, mice, and rats ; to the two 

 latter animals it is commonly fatal ; the disease is readily 

 transmissible from animals to man. The favus patches are 

 distinguished by their yellow colour, their peculiar smell, 

 and their slightly cup-shaped appearance. 



Tricophyton Tonsurans. 



This fungus, which is the cause of herpes tonsurans, 

 ringworm, onychomycosis, and certain other affections, was 



Fig. 21. 



-Trichophyton Tonsubans. 

 filaments.) 



(Myeelia and segmented 



first described by Malsten, a Swedish microscopist, and 

 about the same time by Gruby. 



The organism, which belongs to the oidium group, was 

 first cultivated by Leslie Eoberts, who obtained growths in 



