Within the history of microbiology, Vinogradskii’s study of
Beggiatoa (pp. 48e70) contributed a new, enlightening chapter to
the debate between monomorphism and pleomorphism. Monomorphists
led by Ferdinand Cohn and Robert Koch believed every
species of microbe to have a very stable morphological appearance
throughout its life. Monomorphism was crucial in attempting to
prove that one and only one species of microbe was the causative
agent for each infectious disease. Pleomorphists, such as E. Ray
Lankester, Wilhelm Zopf, and Eugenius Warming, emphasized that
any given microbe could undergo dramatic morphological changes,
based on its physiological response to varying environmental
conditions. Variations in shape and physiological activity were so
great that some pleomorphists such as Nägeli insisted there were
really only a very small handful of microbial species. But in any case,
they feltdin direct contradiction to Cohn and Kochdthat stable
Linnaean species were the exception in the microbial world rather
than the rule. Ackert subjects Vinogradskii’s views on this subject to
a fine-grained analysis, so that we become aware of a new, intermediate
position in this controversy, based on the cycle of life
concept (pp. 56e58).
Cohn gave us the classification system of bacteria based on their
shape: coccus, bacillus, or spirillum. Vinogradskii originally trained
in plant physiology rather than traditional botany as Cohn had.
Thus, he saw physiological characteristics as much more compelling
features than Cohn’s purely morphological properties upon
which to base a microbial classification system. In that sense,
Vinogradskii sided with the pleomorphists. Albeit he did believe in
stable microbial species, but for different reasons than Cohn. His
reading of Pasteur