TINEA. FAVUS 535 



moisture and oxygen supply, endogenous sporulation occurs. As the 

 spores produced are definite in number— two in some species and four in 

 others — the sporangium is an ascus and Saccharomyces is a degenerate 

 ascomycete. While in yeasts generally the oval cell represents the vege- 

 tative unit, in certain species elongated tube-like bodies may be formed 

 which suggest an attempt at hyphal formation. In Saccharomyces my co- 

 derma, the vegetative cells are so elongated and linked as to form a kind 

 of simplified mycelium. 



Fungi imperfect! : Oospora lactis (Fres.) ( = Oidium lactis).— -This 

 is a common fungus in sour milk and sour bread, and can easily be 

 cultivated on gelatin, where the colonies consist of short and fine septate 

 filaments radiating from a centre. Here and there the hypha; are 

 divided, especially at the ends, into short oval or cylindrical segments, 

 termed oidia, which act 'as spores. No other method of reproduction is 

 known. 



It is probable that near to, or in, this unnatural genus- Oospora, should 

 be placed the fungi causing tinea and favns. Many other fungi associated 

 with disease processes in human beings are to be grouped among the 

 Fungi imperfect!. 



Tinea. Favus. 



In dealing with the common fungoid infections of the skin, it 

 is only possible here to give a short account of the methods 

 employed in the investigation and of the more common types of 

 fungi isolated. 



Methods. — For ordinary purposes of diagnosis it is usual to place the 

 epidermic scales or hairs in a solution of 7 grms. of potash in 100 c.c. of 

 water (Adamson) or in liq. potasste (B.P.), to heat for a few seconds and 

 to examine under a cover-glass. For permanent stained preparations 

 Sabouraud recommends that the fat should first be removed by means of 

 chloroform from the material, which is then placed in formic acid and 

 warmed for two or three minutes till the fluid boils. The acid is removed 

 by washing in distilled water and the preparation stained for a minute 

 with Sahli's blue, which has the following composition : Distilled water, 

 forty parts ; saturated aqueous solution of methylene-blue, twenty-four 

 parts ; 5 per cent, solution of borax, sixteen parts ; it is then washed, 

 dehydrated in absolute alcohol, cleared in xylol, and mounted in balsam. 



The glucose and maltose media of Sabouraud (p. 53) constitute the 

 best means of isolating skin fungi, as by these not only are the most 

 characteristic growths obtained, but there is a certain degree of inhibition 

 of the omnipresent skin cocci. Where, as in tinea cireinata, there is a 

 vesicular or pustular lesion, the contents are squeezed out and transferred 

 with a platinum needle to the medium. Where there is a skin scurf, the 

 squames may be scraped off on to a sterile slide from which tubes may be 

 infected. Where hairs are to be dealt with, these may be picked out on 

 to a sterile slide, their roots cut off with a hot needle and planted in the 

 medium. In certain hair affections, especially in animals, the parasite is 

 specially abundant in the aerial part of the hair, so that portions of this, 

 as well as the radical, ought to be used. It is often advisable, especially 

 in pustular conditions and in favus, to place the hair in absolute alcohol 

 for two minutes, to allow to dry and then plant on the medium. 



