y lie in water at a constant temperature
of from 60 deg. to 65 deg. F., it will be seen that the fermentative process
is the work, not of one organism, nor, judging by the standard of our
present knowledge, of one specified class of vegetative forms, but by
organisms which, though related to each other, are in many respects
greatly dissimilar, not only morphologically, but also embryologically,
and even physiologically.

Moreover, although this is a matter that will want most thorough and
efficient inquiry and research to understand properly its conditions,
yet it is sufficiently manifest that these organisms succeed each
other in a curious and even remarkable manner. Each does a part in the
work of fermentative destruction; each aids in splitting up into lower
and lower compounds the elements of which the masses of degrading
tissue are composed; while, apparently, each set in turn does by vital
action, coupled with excretion, (1) take up the substances necessary
for its own growth and multiplication; (2) carry on the fermentative
process; and (3) so change the immediate pabulum as to give rise to
conditions suitable for its immediate successor. Now the point of
special interest is that there is an apparent adaptation in the form,
functions, mode of multiplication, and order of succession in these
fermentative organisms, deserving study and fraught with instruction.

Let it be remembered that the aim of nature in this fermentative
action is not the partial splitting of certain organic compounds, and
their reconstruction in simpler conditions, but the ultimate setting
free, by saprophytic action, of the elements locked up in great masses
of organic tissue--the sending back into nature of the only material
of which future organic structures are to be composed.

I have said that there can be no question whatever that _Bacterium
termo_ is the pioneer of saprophytes. Exclude _B. termo_ (and
therefore with it all its congeners), and you can obtain no
putrefaction. But wherever, in ordinary circumstances, a decomposable
organic mass, say the body of a fish, or a considerable mass of the
flesh of a terrestrial animal, is exposed in water at a temperature of
60 deg. to 65 deg. F., _B. termo_ rapidly appears, and increases with a simply
astounding rapidity. It clothes the tissues like a skin, and diffuses
itself throughout the fluid.

The exact chemical changes it thus effects are not at present clearly
known; but the ferment