250 ALCOHOL, VINEGAR, SAUER KRAUT, TOBACCO, SILAGE, FLAX 
mentation, by which there is a rapid rise in temperature, cannot 
be the result of bacterial growth, since it is too rapid and the 
temperature rises too high. There is no evidence to suggest that 
any bacteria can produce a rise as high as 150°, a temperature 
that destroys the life of most organisms. If the rise were due to 
bacteria it would be rather slow, rising only as the bacteria had 
the opportunity to develop, while on the contrary it is very rapid. 
Finally the possibility of making silage in a jar filled with chlo- 
roform vapor shows that bacterla are not necessary for the 
phenomenon. 
But this does not by any means exclude the agency of micro- 
Organisms in the ordinary formation of silage. Bacteria are cer- 
tainly present and, in some cases, they are present in great 
numbers. Some bacteriologists have not been able to find them 
so very abundantly, but this seems to be due to the fact that 
they did not use favorable media in studying them, for when a 
medium is used that is adapted to the silage bacteria, they are 
found in abundance. Certainly, if they are present and develop 
during the fermentation, they must have some effect upon the 
silage. One effect they certainly seem to have. The silage 
turns acid during the ensiling, and this acidity appears here, as 
in other cases which we have noticed, to be a means of preventing 
subsequent putrefactive changes. Without doubt this acidity 
may be attributed in part, if not wholly, to acid-forming bacteria 
growing in the silo. 
Further, there develop in the silage certain prominent flavors 
which contribute largely to its value, and the source of these 
flavors is as yet unknown. Aromatic flavors such as are found 
in silage do not come from respiratory processes, nor do enzymes 
develop such flavors, so far as is known. There are some who 
think, however, that silage flavors are really due to enzyme 
action. But considering the fact that enzymes do not commonly 
produce any such flavors while bacteria do, and also that bacteria 
certainly grow in the silage after the first fermentation is over, 
