20 
HoGG^ on Vegetable Parasites. 
that the cells become oval and bud out in about an hour 
after being added to the wort ; but this change depends as 
much upon temperature and density, of the solution as upon 
the quality of the yeast. It is a well- ascertained fact that 
when yeast is added to distillery wash^ which is worked at a 
higher temperature than brewers^ wort^ fermentation com- 
mences earlier^ and the yeast-cell grows to a much larger 
size. It is_, indeed_, forced in this way much as a plant in a 
hothouse is_, and then obtains to greater perfection in a 
shorter time. It will^ however, be seen that it sooner be- 
comes exhausted ; and now_, if we take a portion of this yeast, 
and add it to barley-wort, and at the same time keep it in a 
temperature of from 60° to 65° Fahr., it ferments languidly, 
and small yeast-cells are the produce. If the yeast is allowed 
to stand in a warm place for a few days it partially recovers 
its activity, but never quite. With such a yeast there is 
always a good deal of torulse mixed with the degenerated 
cells, and sometimes a filamentous mass, which falls to the 
bottom of the vessel ; from this stage it readily passes to that 
of must and mildew j and then becomes a wasteful feeder or 
destroyer. 
With yeast passing to the stage of exhaustion I have seen 
a crop of yeast fungus produced in the head of a strumous 
boy, seven years of age, who was much out of health, and had 
suffered from eczema of the eyelids, with impetigo. The 
disease had obstinately persisted in spite of well-directed 
efforts to remove it. The scabs were frequently examined, 
but no fungus found. The mother, by the recommendation 
of a friend, washed the boy's head every morning for a week 
with stale beer, I saw the child a few days after these wash- 
ings were discontinued, and warm water only used to soak 
the scabs off. On placing portions of the broken hairs on a 
glass slip, and moistening with a drop of liquor potassse, 
spores and torulse were seen in abundance. Represented in 
PI. Ill, fig. 4. 
I have made frequent microscopical examinations since, with 
the same results. Two years have passed, and the disease 
remains, although parasiticidical washings have had a fair 
trial. A change to country air and good diet always does 
more good than medicine in this case. I do not look upon 
this single experiment as at all sufficient to prove the pro- 
duction of the yeast fungus by transplantation into the human 
skin, although it is not very unlike the achorion fungus, or 
that of tinea tonsurans {tricophyton) ; but, taken with many 
negative trials that I made, to introduce both yeast and 
achorion into perfectly healthy skins, without any abrasion of 
