46 Structure and Classification of Micro-organisms 



THE MOLDS. 



In this group it is customary to place a miscellaneous 

 collection of organisms having in common the formation of 

 a well-marked mycelium, but being so diversified in other re- 

 spects as to place them in widely separated groups in the sys- 

 tematic arrangement of the fungi. Some are correctly 

 placed among the " Imperfect fungi," some among the Asco- 

 mycetes, and some among the Phy corny cetes. They are all 

 active enzymic agents and produce fermentative and putre- 

 factive changes. 



Fig. 10. Mucor mucedo: i, A sporangium in optical longitudinal 

 section; c, columella; m, wall of sporangium; sp, spores; 2, a ruptured 

 sporangium with only the columella (c) and a small portion of the wall 

 (m) remaining; 3, two smaller sporangia with only a few spores and no 

 columella; 4, germinating spores; 5, ruptured sporangium of Mucor 

 mucilaginus with deliquescing wall (m) and swollen interstitial substance 

 (z); sp, spores (after Brefeld). 



1. Ackorion. The organisms of this genus are character- 

 ized by a more or less branched hypha, 3 to 5 ^ in diameter, 

 which break up after a time into rounded or cuboidal spores. 

 The Achorion schonleini is highly pathogenic and will be 

 described in the section upon Favus. 



2. Tricophyton and Microsporon. These names are applied 

 somewhat loosely to organisms affecting skin and hair fol- 

 licles of men and animals. They form tangled slender my- 

 celia with many spores of varying size. They occasion 



