Staining, shape and arrangement of bacterial flagella.

TL;DR: The flagella staining technique to be described is a modification and perfection of that originally published by the author in 1930 and appears to be a characteristic of sufficient stability and distinctiveness to justify the classification of flagellated bacteria into several groups.

Abstract: The flagella staining technique to be described is a modification and perfection of that originally published by the author in 1930. The arrangement and, to a lesser extent, the shape of flagella are of considerable taxonomic importance. Flagellar arrangement seems to be a characteristic of sufficient stability and distinctiveness to justify the classification of flagellated bacteria into several groups. Only rarely, and then mainly with very poorly flagellated bacteria, is the flagellar arrangement difficult to determine. Mutation from one type of flagellar arrangement to another has not, to my knowledge, been described and confirmed. Variation from flagellated to nonflagellated types is common in some groups of bacteria, and several instances have been recorded of loss of motility without loss of flagella (Knaysi, 1933; Kauffmann, 1939; Edwards et al., 1946; Hirsch, 1947; Friewer and Leifson, 1951). The shape of the flagella on an organism, while usually quite characteristic, may be modified somewhat by the environment and also may undergo distinct mutational variation (personal observation). A comprehensive review of the literature is given by Houwink and Van Iterson (1950).