The Story of Germ Life | Page 2

scientists. Today they are almost household words, and
everyone who reads is beginning to recognise that they have important
relations to his everyday life. The organisms called bacteria comprise
simply a small class of low plants, but this small group has proved to
be of such vast importance in its relation to the world in general that its
study has little by little crystallized into a science by itself. It is a
somewhat anomalous fact that a special branch of science, interesting
such a large number of people, should be developed around a small
group of low plants. The importance of bacteriology is not due to any
importance bacteria have as plants or as members of the vegetable
kingdom, but solely to their powers of producing profound changes in
Nature. There is no one family of plants that begins to compare with
them in importance. It is the object of this work to point out briefly
how much both of good and ill we owe to the life and growth of these
microscopic organisms. As we have learned more and more of them
during the last fifty years, it has become more and more evident that
this one little class of microscopic plants fills a place in Nature's
processes which in some respects balances that filled by the whole of
the green plants. Minute as they are, their importance can hardly be
overrated, for upon their activities is founded the continued life of the
animal and vegetable kingdom. For good and for ill they are agents of
neverceasing and almost unlimited powers.
HISTORICAL.

The study of bacteria practically began with the use of the microscope.
It was toward the close of the seventeenth century that the Dutch
microscopist, Leeuwenhoek, working with his simple lenses, first saw
the organisms which we now know under this name, with sufficient
clearness to describe them. Beyond mentioning their existence,
however, his observations told little or nothing. Nor can much more be
said of the studies which followed during the next one hundred and
fifty years. During this long period many a microscope was turned to
the observation of these minute organisms, but the majority of
observers were contented with simply seeing them, marvelling at their
minuteness, and uttering many exclamations of astonishment at the
wonders of Nature. A few men of more strictly scientific natures paid
some attention to these little organisms. Among them we should
perhaps mention Von Gleichen, Muller, Spallanzani, and Needham.
Each of these, as well as others, made some contributions to our
knowledge of microscopical life, and among other organisms studied
those which we now call bacteria. Speculations were even made at
these early dates of the possible causal connection of these organisms
with diseases, and for a little the medical profession was interested in
the suggestion. It was impossible then, however, to obtain any evidence
for the truth of this speculation, and it was abandoned as unfounded,
and even forgotten completely, until revived again about the middle of
the 19th century. During this century of wonder a sufficiency of
exactness was, however, introduced into the study of microscopic
organisms to call for the use of names, and we find Muller using the
names of Monas, Proteus, Vibrio, Bacillus, and Spirillum, names which
still continue in use, although commonly with a different significance
from that given them by Muller. Muller did indeed make a study
sufficient to recognise the several distinct types, and attempted to
classsify these bodies. They were not regarded as of much importance,
but simply as the most minute organisms known.
Nothing of importance came from this work, however, partly because
of the inadequacy of the microscopes of the day, and partly because of
a failure to understand the real problems at issue. When we remember
the minuteness of the bacteria, the impossibility of studying any one of
them for more than a few moments at a time --only so long, in fact, as it

can be followed under a microscope; when we remember, too, the
imperfection of the compound microscopes which made high powers
practical impossibilities; and, above all, when we appreciate the
looseness of the ideas which pervaded all scientists as to the necessity
of accurate observation in distinction from inference, it is not strange
that the last century gave us no knowledge of bacteria beyond the mere
fact of the existence of some extremely minute organisms in different
decaying materials. Nor did the 19th century add much to this until
toward its middle. It is true that the microscope was vastly improved
early in the century, and since this improvement served as a decided
stimulus to the study of microscopic life, among other organisms
studied, bacteria received some attention. Ehrenberg, Dujardin, Fuchs,
Perty, and others left the impress of their work upon bacteriology even
before the