THE PATHOGENIC FUNGI 995 



lactose. Spores are very numerous and often provided with short sterigmata. 

 Five other pathogenic varieties are listed by de Beurmann and there are 

 many saprophytic species. Wolbach 34 has described a species isolated from 

 an arthritis of the knee which he named Sp. Councilmanni. 



Pathogenicity. Spontaneous infections due to the sporotrichum 

 Beurmanni have been observed in rats, dogs and horses. Experi- 

 mentally cultures have been shown to be virulent for rats and other 

 laboratory animals. 



The pathogenic species seem capable also of saprophytic existence. 

 De Beurmann recovered his species from the normal throats of 

 patients with sporotrichosis and of others who had recovered from 

 the disease. Gougerot found in oat grains, and in other plants 

 sporothrices which he regarded as identical with the human species 

 and which were virulent for rats. 



Immunity. Widal and Abrami 35 found that suspensions of 

 sporothrix spores were agglutinated by the sera of patients in 

 dilutions 1-200 or above and have used this reaction in diagnosis. 

 They also obtained fixation of complement. Others report that 

 patients give skin reactions with culture extracts. In human cases 

 there is no evidence of the development of an immunity but in 

 animals successful immunization, both active and passive, has been 

 reported. 



DISEASES OP THE RINGWORM GROUP 



There is a group of common and relatively trivial fungus infec- 

 tions called dermatomycoses. In it are included a number of dis- 

 eases clinically distinct, all of which are, however, characterized by 

 the fact that the invasion of the parasite rarely penetrates deeper 

 than the epidermis and its appendages the hair and nails. The 

 fungi causing these infections are known as dermatophytes. They 

 are filamentous organisms resembling in structure the hyphomycetes, 

 in which group they are usually placed. 



Brumpt, Castollani and others prefer to group them with the asco- 

 mycetes. This decision is based partly on their general structural resem- 

 blance to these higher fungi but chiefly ou the observation of Matruchot 



31 irolbach, Sisson and Meier, Jour. Mecl. Res., 1917, CXXXVI, 337. 

 35 Quoted by de Beurmann and Gougerot, loc. cit. 



