4i 
These are minute spherical, or ovoid bodies of an extreme 
tenuity. One needs a very good microscope to distinguish the 
form, for some are no more than four to five-thousandths of a 
millimeter in diameter. They therefore are dispersed in the 
air with the greatest ease, and it may be said that they pene- 
trate everywhere. It appears that the musty odor of closed 
and unventilated places is due to the dissemination of the 
spores of fungi. It is sufficient to plant the spores in suitable 
conditions to reproduce the fungi ; the only difficulty is to 
realize the suitable conditions. The obstacles to obtaining 
these are such that it has been impossible to multiply fungi 
by artificial means, except for the ordinary edible mushroom 
and a few allied kinds. 
We may say that fungi present every color, except green. 
The exclusion of this color is due to the total absence of 
chlorophyl — a substance which plays as we know a principal 
part in the existence of all other vegetation. One immediately 
deduces from this that fungi must possess a life differing radi- 
cally from that of other plans. This is fully confirmed by ex- 
periment. Fungi live, not like vegetation, but like animals ; 
they constantly absorb oxygen and give off carbonic acid ; they 
are incapable of decomposing the latter in order to free the 
carbon. It is therefore absolutely necessary, that this carbon 
should be furnished them by some other means. As a mat- 
ter of fact, fungi can only live on organic matter, sometimes 
living, but usually in a state of decomposition. From this 
they draw the carbon of which they have need, and thus 
destroy the organic matter on which they live. Fungi play 
therefore one of the most important parts in nature. It is they 
who dissolve combinations which have become useless, and 
replace their elements in circulation. A piece of dead wood, 
which for years would remain intact without the help of fungi, 
is destroyed by these in a short time, so that its elements may 
form new combinations and recommence a new cycle. One 
sees by this how beneficial the part played by fungi is. Be- 
sides, we must not understand by this term the few species 
which we eat; they are the infinitesimal minority. I will not 
say that the varieties of fungi are innumerable, for the patience 
of systematic classifiers is without limit, but they may be 
counted by the thousand. All forms of mildew, which attack 
bread, cheese, old w r ood, etc., are fungi. The ferments which 
transform the juice of the grape or the apple into wine- or 
cider are fungi. Almost all germs which cause fermentation 
are fungi. Fungi again, but to which the epithet of beneficial 
cannot be applied, are most of the organisms which attack the 
grape vine ; oidium, mildew, black rot, etc. Some years ago, 
botanists had listed three hundred and sixty parasitical fungi 
of the grape. Rust and the caries of wheat, ergot of rye, the 
potato disease, are due to fungi. It is the same thing with such 
