118 PHYSIOLOGY OF THE BACTERIA. 
he says, “ that the complete development of Bacil- 
lus, and above all reproduction by means of spores, 
is only made under the influence of free access 
Gi rain: | 
We might explain the contradictory facts of 
Pasteur by admitting, with Cohn, that the appear- 
ance of different réles played by the aerobies 
(Bacterium) and the anaeérobies (Bacillus) is sim- 
ply due to a veritable struggle for existence which 
takes place between the microbacteria and the 
desmobacteria. 
ACTION OF VARIOUS AGENTS UPON THE BACTERIA. 
In this paragraph I shall pass in review the 
action of temperature, of movement, and of va- 
rious antiseptics. 
Temperature. —It is very important to ant 
the manner in which bacteria comport themselves 
under extreme variations of temperature. It is, 
indeed, upon the results furnished by these re- 
searches that a great part of the arguments op- 
posed to the panspermatists by the heterogenists 
are based. 
We shall consider the influence upon bacteria 
of moderate temperatures and of extremes above 
and below zero. 
Moderate temperatures— that is to say those 
which are comprised between 25 and 40° (77 to 
104° Fah.) — are generally favorable. The most 
favorable has been found to be 30° (95° -Fah.) 
(Onimus). 
