PART IV. 



L MYCOSES (INFECTIONS WITH FILAMENTOUS 

 AND BUDDING FUNGI)* 



An incomparably lesser role in the etiology of dis- 

 ease is played by the filamentous fungi (molds) and the 

 budding fungi than by bacteria (fission-fungi). The dis- 

 eases generated by the former are designated mycoses. 



MORPHOLOGY AND BIOLOGY OF THE FILAMENTOUS 

 AND THE BUDDING FUNGI. 



The filamentous fungi are chlorophyl-free, thread-like 

 cells that exhibit progressive apical growth, and that, singly 

 or branched, usually divided into segments by internal 

 septa, unite to form a deposit and at times a dense felt- 

 work of closely interlaced threads (liyphce). This so-called 

 vegetative portion of the fungus is known as thallus (fungous 

 deposit) or mycelium. Distinct from this is the fructifying 

 portion, the fruit-bearer, which arises from the mycelium 

 and bears the fruit (spores or conidid). The spores again 

 grow into threads ; the enlargement takes place steadily 

 through progressive apical growth of the threads, which in 

 turn give rise to new spores. The structure of the fruit- 

 bearing apparatus is so peculiar in a number of filamentous 

 fungi that this external feature has been made the basis of 

 their classification. Of the numerous species of filamentous 

 fungi, running up into thousands, only the following are of 

 pathologic interest : 



i. The Aspergilli (Bulbous Molds], The fruit-hyphae ex- 

 hibit no division ; they swell into the form of a club at the 

 extremity. This bulbous enlargement is densely occupied 

 by short, flask-shaped structures, arranged radially, the in- 



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