THE PATHOGENIC FUNGI 1001 



The study of the morphology of cultures is made difficult by 

 the fact that in detaching pieces for observation from the tough 

 mass of growth the spores are usually detached and characteristic 

 mycelial structures deformed or broken up. Certain points can be 

 made out by examining such fragments mounted in water in an 

 unstained condition but more information can be gained from the 

 study of hang-drop cultures. These are made by placing a large 

 drop of 4 per cent maltose broth on a sterile cover slip inoculating 

 it with a fragment of the culture and inverting over a hollow slide 

 with a deep concavity. This may be sealed with sterile oil or 

 petrolatum. 



FAVUS 



Favus is a disease usually limited to the scalp but which occasion- 

 ally attacks the glabrous skin and the nails. It is characterized by 

 the formation at the mouths of the hair follicles of small yellow cup- 

 shaped crusts known as scutula. It is found in adults as well as in 

 children and in this country occurs chiefly among immigrants from 

 eastern and southern Europe where it is endemic. 



ACHORION SCHOENLEINI 



Favus of the scalp is caused by one species of fungus the 

 Achorion Schoenleini. A scrutulum when crushed in alkali is found 



FIG. 114. ACHORION SCHOENLEINII. Section of favus crust. Stained by Gram 

 (After Fraenkel and Pfeiffer.) 



to be composed almost entirely of the fungus. The central portion 

 is made up of rounded sporelike bodies of varying size without 

 definite arrangement. Toward the periphery similar elements are 



