HoGG^ on Vegetable Parasites. 
21 
surface, I think it has an important bearing on the sub- 
ject of ray paper. At all events it is a fair illustration of 
change of type,"^ for when Mr. Hunt saw the boy, after the 
disease had persisted for at least twelve months, he at once 
pronounced it to be pityriasis rubra or versicolor. Had the 
fungus played any part in bringing about this change in the 
character of the disease ? 
In another experiment I took portions of some penicillia 
and aspergilli moulds, and upon adding these to sweet wort 
I obtained results confirmatory of Dr. Lowe^s,t which were 
pretty much as follows. Having placed small quantities of 
spores in the wort, I stood them by in a warm room. 
On the second day in one of the solutions, and on the third 
in the other, fermentation had fairly set in ; the surface of 
the solution was covered with a film, which proved to be well 
developed ovoid spores, filled with smaller granular spores 
(conidia) (fig. 5, PI. IV) . On the sixth day the cells changed 
in form, and were more spherical. Again removing these to 
another supply of fresh wort, the results obtained were quite 
characteristic of exhausted yeast ferment. J 
* The Rev. Mr. Berkeley, in his 'Outlines of British Fungology,' writes : 
— " It is not possible that in these cases fungi originate disease, though it is 
pretty certain that they frequently aggravate it." Nevertheless, after this 
clearly expressed and positive statement, we find, a few pages further on, 
the following contradictory assertion : — " That a few spores rubbed into the 
skin or inserted in it will soon i)roduce the disease known as porrigo lupinosa" 
(favosa ?). And he cites Dr. Lowe as his authority for this statement ; but 
on looking over this gentleman's writings, what do we find ? Why, that in 
the course of a somewhat extended inquiry into the causes of diseases of the 
skin he only met with two cases in brewers' draymen, and one in a dirty 
cellarman, of parasitic growths, with sycosis and favus, and which, he tells 
lis, commenced with a sore. I would ask any one conversant with these 
diseases if this at all justifies the above assertion, or proves that the parasite 
can be communicated to, and grown upon, the healthy human skin. For my 
own part, so thoroughly satisfied am I of the utter fallacy of such a statement, 
that I should have no hesitation in submitting my own skin to be experi- 
mented upon to test the truth of what I have stated. 
f It is only right to say that I did not follow Dr. Lowe, as some writers 
have stated, in this field of inquiry. My observations on skin diseases were 
commenced at the suggestion of my friend Mr. Hunt, in 1856, and continued 
for three years before my first paper appeared in print. At that time, 1859, 
neither Mr. Hunt nor myself had heard of Dr. Lowe's researches, which, it 
appears, were communicated to a local society, and published in the 
'Edinburgh Botanical Society's Transactions,' 1857. 
% Directions for preparing and mounting. — The mode of preparing 
specimens of fungi for the microscope. — After having removed a small portion 
of the crust or a hair from the affected part, place it on a glass slip, and 
gently separate the mass with needle-points, and add a drop of liquor 
potasses, which will render it transparent ; then cover with a piece of thin 
glass and remove any superfluous fluid with a small piece of blotting-paper. 
