59 
It is the minute, microscopic fungi, the schizomycetes, or 
those that propagate by simple division, that we specially consider 
to-night. You know them as microbes, bacilli, bacteria. 
For the most part they are either moulds or yeasts, and I 
wish to show you that they cause disease in plants in exactly 
the same way as many of you already know they cause disease 
in man and animals. 
They are very minute microscopic fungi, and Professor \\. 13 . 
Bottomley described in a lecture in Bournemouth a few days ago, 
how he estimated that from 30,000,000 to 50,000,000 of them could 
lie on a postage stamp, another reason for not carrying out the 
stamp-licking details of the Insurance Act. 
They vary in shape, some (the micrococci) being mere dots, 
others short rods, while still others are spiral or are furnished 
with fine processes (flagelli). 
According to the soil they live on, they used to be divided 
into saprophytic, or those which live on dead material, and para¬ 
sitic, or those which liv e on the juices of living plants or animals, 
but these terms were not iound to cover the whole ground, and 
pathogenic, or those which cause disease, and non-pathogenic, or 
those which do not cause disease, are now recognised as more 
suitable terms for their classification. 
Some live better in an atmosphere of oxygen, others in an 
atmosphere of hydrogen. 
Sunlight has a deadly effect on most, a dark cupboard or 
damp cellar being their happiest habitat. Many of them produce 
colour chiefly by means of their spores, and some secrete fetid 
gases. 
They are recognised by their mode of growth on various 
gelatines, agar agar, and such like, and whether they liquify or 
not, such a culture medium is an important agent in their identifi¬ 
cation. 
In fact, the pathologist sows these fungi of disease on his 
culture medium and recognises them very much as the gardener 
sows turnips, carrots or lettuce. 
The making of wine, and no doubt the drinking of it, were 
known to the ancient Egyptians long before the time of Christ, 
but it was not till Schwann discovered the yeast lungus in 1838 
that anything was known about the cause of the various changes 
which occur during the process of wine making. 
Later, Pasteur went to a meeting of the Academy of Sciences 
in Paris and stated that the yeast fungus was the cause of the 
fermentation of grape sugar in grape juice. They laughed 
at him, but he produced albs, of Algerian grapes and said to 
them: “ Here are two flasks, you shall take one and I shall 
keep the other. Into your flask you can press the juice of your 
lb. of grapes, and into mine I will do the same, the only stipula¬ 
tion I make, is that you should allow me, with a clean silk hand¬ 
kerchief, to carefully wipe the stalks and skins of my grapes, 
on which the yeast fungus lives. We shall meet here in a month, 
