998 THE HIGHER BACTERIA, MOLDS AND FUNGI 



microspora they are attached to the fertile hyphae by a flattened facet so 

 that they resemble abortive branches (Aeladium type). In the tricophyta 

 they are more frequently attached by a pointed tip (Botrytis type). Often 

 they are scattered irregularly along the hyphae, but occasionally show a 

 characteristic arrangement. Groups of conidia formed along the sides of 

 an unbranched terminal hypha Sabouraud calls thyrses, larger groups born 

 on branched conidiophore clusters (grappes}. 



Pectinate bodies are swollen and usually curved ends of hyphae which 

 give off a row of abortive branches from one side the structure vaguely 

 resembling a comb. 



Spirals. These are simply convoluted hyphae which may take all the 

 forms of a tendril from a spirillum-like form to a close set coil. 



Nodular organs. These are chains of large rounded cells knotted together 

 into small dense masses suggesting the sclerotia of higher fungi. 



Pleomorphism. The gross appearance and microscopic structure 

 of the dermatophytes varies greatly with the cultural conditions. 

 After a period of growth on sugar containing media they seem 

 to undergo a permanent change, ceasing to produce conidia and 

 developing a thick covering of very long aerial hyphae. This gives 

 to these altered cultures a smooth white downy appearance. 

 Sabouraud refers to cultures of this type as Pleomorphic using the 

 term here in a special sense. The altered forms of different species 

 resemble each other closely so that the identification of a culture 

 by its gross or microscopic appearance is often almost impossible 

 once this change has taken place. 



Pathogenicity. The ringworm fungi are found with such 

 regularity and in such profusion in many of the human lesions as 

 to leave little doubt as to their causative relationship to the disease. 

 Many of the same species are found, too, in similar lesions of 

 domestic animals. These latter will also induce lesions in guinea- 

 pigs with more or less regularity if culture fragments are inserted 

 in the skin. Such experimental lesions are often transitory but 

 resemble somewhat the spontaneous disease. Other species such as 

 the Microsporon Audouim and Epidermophyton inguinale, mentioned 

 below, although found abundantly in characteristic human lesions, 

 have not been found in animals and are innocuous when experi- 

 mentally injected. 



Concerning the power of the dermatophytes to produce systemic disease 

 we have little information. Their entire lack of invasive power in the 

 spontaneous infections is quite striking. The isolated reports of Sabrazes 



