HoGG^ on Vegetable Parasites. 
11 
visible though they be to the unaided sights are nevertheless 
produced in myriads in the earthy air^ and water around us^ 
and are so diminutive that ordinary motes floating about in 
the atmosphere are large in comparison. And when we 
reflect on the very remarkable powers of life possessed by all 
— and the fungi m particular — Avhich are found to resist 
a moist heat equal to that of boiling water, and also an in- 
tense frost, without at all losing their powers of germi- 
nation, we can no longer feel surprised that their spores are 
found penetrating the hairs of the head or the hair-follicles 
and epidermic cells of the body; nor, indeed, that they 
should penetrate the internal parts, even where the hard tex- 
tures, the bones, do not escape their destructive influence. 
For the very reason that these pests, botrytaceous or myco- 
dermatous fungi, are found both upon the external and in- 
ternal surfaces, it is proposed to divide them into Epiphytes 
and Entophytes. 
Although, as I have before pointed out, it is not possible 
that in either of these cases fungi originate disease, it is 
pretty certain that they frequently aggravate it, and once 
let the spores establish themselves on any part of the body 
where the secretion is not sufficiently active or healthy, and it 
is a difficult matter to throw off* the intruder. 
These, then, were exactly the conclusions I had arrived at 
seven years ago, and since this subject has engaged the atten- 
tion of our countrymen, it appears that men who are deservedly 
eminent on the Continent have been led to examine into the 
truth of these researches, and the result has been that Bazin, 
Hebra, and others, have considerably modified their views 
and reduced the number of species. 
It will, however, assist our investigation if I enter very 
degraded, it may obtain a power of indefinite multiplication, like the pus of 
an abscess or the secretion from purulent ophthalmia. Such pus, that is, 
such degraded germinal matter, he has shown to have the power of inde- 
pendent growth under various conditions, and to be capable of maintaining 
its vitality for long periods, if not completely deprived of moisture. When 
introduced into another animal's body, offering favorable conditions, it in- 
creases and multiplies. It would appear, then, that the growth of ill-con- 
ditioned germinal matter may be accompanied by the development of poison 
in the organism that supports it; just as the growth of mould changes the 
quality of bread, or cheese, or other substance, on and in which it is found. 
He does not, however, assume the existence of spores or other bodies, whose 
presence he has not yet discovered, but appeals rather to the germinal 
matter whose existence and growth lie has demonstrated ; and although he 
does not look for the extinction of all contagious diseases, yet he does expect 
that much good will be derived from keeping the body in an unsusceptible state 
— by living in good and pure air, by dryness and plenty of sunlighl, and es- 
pecially by general cleanliness, as preventives of these forms of disease. 
