404 VETERINARY BACTERIOLOGY 



that the evidence of pathogenesis rests entirely upon the constant 

 occurrence of the organism in the disease in question. Itch- 

 mites (Sarcoptes equi) were found, but the investigators believe 

 their numbers insufficient to account for the disease. It is entirely 

 possible that the organism is a secondary invader, or produces the 

 disease in a kind of symbiotic relationship with the Sarcoptes. 

 The fungus seems to enter the hair-follicles, penetrates between 

 the epidermal cells, and involves the surrounding skin, causing 

 an intense itching. The body becomes covered with a crust or 

 scurf, at first gray and afterward darker. The presence of the 

 organism in the hair-follicles causes the hairs to fall out, resulting 

 in an almost complete alopecia. 



THE GENUS SPOROTRICHUM 



Authorities differ greatly in the delimitation of this genus. 

 According to botanists, the genera Microsporon and Trichophyton 

 are synonyms of Sporotrichum. Pathologists and bacteriologists 

 in general, however, make a distinction between them. The 

 classification of the latter will be adopted here and the term Sporo- 

 trichum used in the narrow sense. 



Sporotrichum is distinguished by the production of definite 

 hyphae, which are usually creeping and irregularly branched. 

 Definite conidiophores are not developed, or consist only of small 

 side branches. The conidia are borne either on the sides or ends 

 of the hyphae, singly or in clusters. They are usually very numer- 

 ous, ovoid or spherical in shape, and hyaline or rarely lightly 

 colored. The molds belonging to this group are in need of careful 

 study and revision, as there is great uncertainty concerning many 

 of the species. 



One, or possibly two, species of Sporotrichum have been shown 

 recently to be of considerable pathogenic significance. 



Sporotrichum beurmanni 



Synonym. Fossil >ly Sporotrichum schenkii. 



Disease Produced. Sporotrichosis in man and animals, one 

 typi! of epizootic lymphangitis in horses. 



Schenk, in 1898, and Hoktoen and Perkins, in 1900, described 

 a species of Sporotrichum causing multiple abscesses in man. 



