er any
modification on account of the air is easily conceived; but it is
conceivable not less easily that if there should be any change it would
occur by preference in the case of a mycelian fragment. It is thus that
a slip which may have been abandoned in the soil in contact with the air
does not take long to lose all vitality, while under similar conditions
a seed is preserved in readiness to reproduce the plant. If these views
have any foundation, we are led to think that in order to prove the
action of the air upon the anthrax bacteria it will be indispensable to
submit to this action the mycelian development of the minute organism
under conditions where there cannot be the least admixture of
corpuscular germs. Hence the problem of submitting the bacteria to the
action of oxygen comes back to the question of presenting entirely
the formation of spores. The question being put in this way, we are
beginning to recognize that it is capable of being solved.

"We can, in fact, prevent the appearance of spores in the artificial
cultures of the anthrax parasite by various artifices. At the lowest
temperature at which this parasite can be cultivated--that is to say,
about +16 degrees Centigrade--the bacterium does not produce germs--at
any rate, for a very long time. The shapes of the minute microbe at this
lowest limit of its development are irregular, in the form of balls and
pears--in a word, they are monstrosities--but they are without spores.
In the last regard also it is the same at the highest temperatures at
which the parasite can be cultivated, temperatures which vary slightly
according to the means employed. In neutral chicken bouillon the
bacteria cannot be cultivated above 45 degrees. Culture, however, is
easy and abundant at 42 to 43 degrees, but equally without any formation
of spores. Consequently a culture of mycelian bacteria can be kept
entirely free from germs while in contact with the open air at a
temperature of from 42 to 43 degrees Centigrade. Now appear the three
remarkable results. After about one month of waiting the culture
dies--that is to say, if put into a fresh bouillon it becomes absolutely
sterile.

"So much for the life and nutrition of this organism. In respect to its
virulence, it is an extraordinary fact that it disappears entirely after
eight days' culture at 42 to 43 degrees Centigrade, or, at any rate, the
cultures are innocuous for the guinea-pig, the rabbit, and the sheep,
the thre