40 
HoGG^ on Parasitic Fungi. 
was seen^ without any reference to artificial classification on 
the one hand^ or to pathological theory on the other ; and 
careful drawings have been made from my sketches by Mr. 
Arthur Hunt to illustrate this paper. The cases examined 
are distributed among fourteen genera of Willan^s classifica- 
tion of cutaneous diseases, namely, in Porrigo, Psoriasis, 
Pityriasis, Sycosis, Lepra, Lupus, Lichen, Impetigo, Furun- 
culus. Eczema, Vitiligo, Spilus, Ichthyosis, and Acne. The 
filaments or spores of a cryptogamic plant were found in all 
the genera excepting Impetigo, Furunculus, Vitiligo, and 
Acne, and, I think, we must add Lupus, in which genera the 
examinations happen to have been few in number. In four 
distinct diseases arranged under three of these genera, viz., 
1st, Porrigo decalvans, or Tinea decalvans, or Alopecia cir- 
cumscripta ; 2d, Porrigo scutulata, or. Tinea tonsurans, or. 
Herpes tonsurans ; 3d, Pityriasis versicolor, or P. lutea or 
Cloasma ; 4th, Sycosis or Mentagra : in these forms fungi 
had been seen by previous observers, as also in Porrigo favosa ; 
but in the other six diseases, viz., Psoriasis, Lepra, Lichen, 
Eczema, Spilus, and Ichthyosis, no author had reported any 
observations of the kind : and so certainly have these dis- 
eases been considered free from vegetations, that they have 
not been included with the five above-named diseases, and 
on which the name Dermatophyta has been bestowed. There 
are probably reasons why the parasite should not so fre- 
quently be met with in these seven diseases ; but I have, 
nevertheless, found them in the instances related, although 
not in all those examined, as the following record will show. 
Analysis of Cases. 
At the head of my list I placed Favus, but this disease is 
so rarely seen, either at the Dispensary for Diseases of the 
Skin, or in private practice, that I have not been fortunate 
enough to obtain a specimen for examination. Although so 
rare here, it appears to be particularly well known on the 
Continent, and, consequently, has received much attention. 
Schoenlein was the first to describe the vegetable character of 
the favi, and to make a drawing of the filaments and granu- 
lated stroma; this fungus is, therefore, called after its disco- 
verer, Achorion Schoenleinii. Gruby described more accu- 
rately its mycelium and spores. We are told by them that 
Favus is frequently followed or accompanied by Pity- 
riasis, Eczema, and Impetigo, and is therefore liable to be 
confounded with the fungus of Trichophyton tonsurans, from 
which it is to be distinguished by observing the difference in 
