Further Studies on the Life Cycle of the Avian Tubercle Bacillus

Abstract

Summary

Dissociation of the tubercle bacillus into a heterogeneous non-acid-fast progeny and its occasional reversion to the original is a very old observation. The S and R variability reversions are more recent, while demonstration of a filtrable phase (granules of Much and their congeners) for pure cultures is quite recent. The sum total of these observations constitutes a collection of “variability fragments”, so to speak; but it requires orderly allocation by experiment to dispel the chaos that they have represented to monomorphic theory.

These studies represent, I believe, the first experimental integration of these several “variability fragments” in accordance with a single unifying conception, namely, the biologic sequences of a true life cycle. Single-celled cultures only have been employed. The variability of the non-acid-fast progeny is of such a character as to suggest strongly its implication with the genetic mechanism of the cell, which accounts in part for the following paper.