MICROSCOPICAL DIAGNOSIS. 



59 



"tinese." There are the following varieties : tinea favosa, tinea 

 circinata, tinea tonsurans, tinea sycosis, and tinea versicolor. 



Fig. 14. Achorion Schonleinii. 



Tinea favosa, favus, or crusted ringworn, is due to the 

 presence of a vegetable parasite called achorion Schonleinii. See 

 fig. 14. Under a power of four or five hundred diameters this para- 

 site is seen to consist of both mycelium and spores in great quanti- 

 ty. The mycelium is composed of narrow tubes or threads of 

 varying length. It is usually very abundant. It differs greatly 

 in appearance with the stage of its growth, for the tubes may 

 appear perfectly empty or they may contain spores, in which 

 case they are called "receptacles" or "spore- 

 tubes." These tubes look like links of chains, 

 some of the links being found single, in others 

 united," two or more 'together, and all inter- 

 mingled with the spores. The spores are 

 very irregular in shape ; they may be round, 

 oval, dumb-bell, or flask-shaped. They vary 



n 



size from ^TOO to ToW f an mcn 



size. They are highly refractile bodies and 

 have a grayish or pale-greenish color. They 

 exist in vast quantities and are everywhere 

 Fig. 75. Split //tf//--P resent m tne specimen examined. This 

 shaft showing spores. fungus is the most luxuriant of the vegetable 

 parasites. To examine for them, a small part of a crust or 

 hair should be placed on the slide and covered with the thin 

 glass. A drop of liquor potassae is placed to the edge of the 

 cover and allowed to come in contact with the specimen. A 



