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Se 
39 
of the question to go and look for some diatoms to inspect, 
we must go and ask the nearest brewer for a little yeast. The 
hot and busy workman grants our petition, wondering the 
while at the satisfaction with which we receive what is not 
enough to leaven a baking for the smallest of fairies, or in- 
fluence, at least for some time, the wort in which it is floating. 
Delighted with our prize we hasten home, place a minute 
portion of it in the animalcule cage, with a small drop of 
warm wort for it to float in, and we slip it in with eager inte- 
rest beneath the low power of the Microscope. Here we 
have at once the first and most curious exemplification of a 
simple cell. This well-known fungi is called the Yeast Plant, 
and consists of two parts, the cell wall, composed of a matter 
called cellulose, and the contents of the cell resembling fat 
or oil. The notion that Yeast was an organised being, in 
fact, a living plant, was at first strongly opposed by some of 
the first men of science. The Microscope, however, has con- 
vinsed them both of its organisation and vitality! It consists 
of globular or egg like transparent cells with a nucleus or 
spot. To watch its changes with efficiency it must always be 
mixed with a small quantity of newly-made beer. One hour 
after it has been added to the wort germination commences, 
and two buds, or cells, are produced on either side of the 
parent cell. Eight hours after the plants begin to ramify, or 
throw out slender fibres, some exploding and emitting a fine 
powder. In three days pointed filaments with lateral branches 
are produced. Suchare the changes to be seen by the patient 
Microscopist, who will thus have had an insight into the 
manner in which the germination and reproduction of the 
first life form is conducted. There are other forms of Yeast 
Plant existing under different circumstances, even in the human 
body ; but as these few remarks are only to call attention to the 
wonders every-day life may furnish to our Microscopes, they 
are beyond our reach, indeed, strictly confined to the search 
of professional or highly scientific men. It may content us 
to know that the governing laws which influence them, are 
the same as those governing the common Yeast Plant of beer. 
Of the same sort of one-celled plants is the fungi, or mildew 
blighting grapes. ‘‘Grapes,” says Mr. Harris, “‘when blighted, 
are covered with what appears to be a white powder like lime, 
a little darkened with brown or yellow. These dark spots are 
