THE MICROSCOPE IN AETIOLOGY. 329 



tagra (sycosis), eczema marginatum, etc. It is thought by 

 some to proceed from aspergillus. 



In examining hair, skin, etc., for fungi, the specimens 

 should be soaked in liquor potassse long enough to become 

 transparent. 



2. Achorion Schonleinii Favus Fungus. Mycelia com- 

 posed of small, simple, or branching tubes divided by par- 

 titions. Spores round or oval, sometimes grouped in 

 masses. The cause of tinea favosa of the scalp. 



3. Microsporon Audouinii. Undulating forked filaments 

 on which spores are directly placed. Found round the 

 shaft of the hair after its exit from the follicle, so thick 

 that the hair breaks off and causes baldness. Porrigo de- 

 ealvans. 



4. Microsporon Furfur. Masses of large, round, mostly 

 nucleated spores, and long or branched cells. Sometimes 

 with numerous broad filaments. Developed in the horny 

 layer of the epidermis, commonly round the opening of 

 hair follicles of the breast and back, producing yellowish 

 discoloration and branlike scales, with itching, Pityria- 



' sis versicolor. 



5. Oidium Albicans Thrush Fungus Tubular fila- 

 ments, branching stems, and minute spores. Ends of fila- 

 ments lost in masses of spores, with a large, often divided 

 spore-cell. Found in aphthae of the mouth, tongue, throat, 

 vagina, etc. 



III. FUNGI AS EXCITORS OF FERMENTATION AND PUTRE- 

 FACTION AND CAUSES OF DISEASE. 



At page 137 the distinction between diseased conditions 

 which invite fungi and the effects produced by fungi 

 themselves was stated. That fungi are the cause of spe- 

 cific fermentations (acetic, alcoholic, lactic, butyric, etc.), 

 is rendered very probable by modern researches, especially 

 those of Pasteur. In decay, or oxidation, and in putre- 



