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;