54 
HoGGj on Parasitic Fungi. 
parasite of its own, differing from this and peculiar to itself, 
and lastly, seeing that attempts have been made in vain to 
implant these parasites to a healthy skin — one cannot bat 
conclude that the whole theory is erroneous, and that para- 
sites peculiar to and productive of special diseases do not exist. 
In this opinion we are at least confirmed by the therapeutical 
fact, that the alleged parasitical affections are rarely, if ever, 
cured by destroying the parasite ; but by the due administra- 
tion of alteratives and tonics, capable of correcting the blood 
dyscrasia, w^hich in fact originates the disease, they most 
assuredly can be cured. 
These views are countenanced by distinguished pathologists. 
Professor Bennett, writing of Favus, says, " I believe that the 
pathology of Favus is best understood by considering it 
essentially to be a form of abnormal nutrition, with exudation 
of a matter analogous to, if not identical with, that of tubercle, 
which constitutes a soil for the germination of cryptogamic 
plants, the presence of which is pathognomonic of the disease. 
Hence is explained the frequency of its occurrence in scrofu- 
lous persons, and among cachectic or ill-fed children ; the 
impossibility of the disease in healthy tissues, or the necessity 
for there being scaly, pustular, or vesicular eruptions on the 
integuments previous to contagion. And in some few ex- 
periments wherein it has been said that inoculation has 
succeeded in healthy persons, the following explanation may 
be offered : — that the material in which the vegetations grow 
may, at the commencement, in a molecular exudation, be 
formed either primarily or secondarily, i. e. there may be 
want of vital power from the first, as occurs in scrofulous 
cases, or there may have been a production of cell-forms, such 
as those of pus or epidermis, which, when disintegrated, and 
reduced to a like molecular and granular material, secondarily 
constitute the necessary ground from which the parasite 
derives its nourishment, and in which it grows. ""^ 
Very nearly the same conclusions have been arrived at with 
regard to the propagation of the moulds among the vegetable 
tribes, which at one time it was said originated by fungi. 
Mr. Henfrey, writing of the development and progress of vine 
fungus, says that it is the cause, and not a consequence of 
the murrain nevertheless, with some caution and suspicion 
of the truth, he adds, there are various curious circum- 
stances connected with it not at all understood, and it is very 
probable that peculiar atmospheric conditions induce predis- 
posing states of the plants.^^ 
It scarcely admits of a doubt, that all the diseases observed 
* Bennett's 'Principles and Practice of Medicine,' p. 307- 
