REVIEWS. 
41 
grows in the hair follicle, and is also found in abundance amongst the epithelium, 
in the neighbourhood. It may be frequently seen within the hair in consider¬ 
able quantities (fig. 8), and may be found in abundance in the little honeycomb¬ 
like masses, termed favus crusts. 
“ The favus consists of a little cavity, filled with spores of the fungus, granules, 
and epithelial cells (fig. 9); one or two hairs usually pass through the centre 
of the favus. The fungus is composed of the mycelium (a\ or the proper sub¬ 
stance of the plant; of a receptacle (6), or sporangium , which contains the repro¬ 
ductive organs; and the reproductive organs them¬ 
selves, or the spores. 
4 ‘ This fungus occurs in Tinea favosa , Porrigo 
favosa , scutulata , &c. The favus may be placed 
upon a glass slide, moistened with water, and 
subjected to microscopical examination. When 
the hair is to be examined, the same course is 
pursued; but it will often be found advantageous 
to treat it with a drop of the solution of potash, 
which renders the hair more transparent and the 
fungus more distinct. 
“ There are several other species of fungi infest¬ 
ing the hair; the Tricophyton tonsurans is found in 
the form of very minute, oval or rounded, per¬ 
fectly transparent cells, within the bulb, and in 
the central canal of the hair. When it occurs 
external to the canal of the hair, its presence de¬ 
pends upon the hair having been broken, and 
the escape of the contents. 
“ Other species are found in the epithelium of the skin. That condition of the 
skin termed Pityriasis versicolor , depends upon the epithelial cells in the coloured 
situations being infested with spores of another of these minute fungi. Cases have 
occurred in which a previously healthy individual has been infected with the disease 
after having slept with a patient suffering from this affection. 
u Parasitic plants are met with in the following skin diseases :_ 
Fig. 10. 
1. Tinea tondens. 
2. Tinea favosa. 
3. Mentagra. 
4. Pityriasis versicolor. 
5. Porrigo decalvans. 
6. Plica polonica. 
VOL. II. 
D 
