Pullulomyxa botrytis n. sp.

A brief note was published some years ago by W. T. Morgan of the Lister Institute, London, and the writer (1932) describing the isolation from decayed woody tissues of a micro-organism which decomposes the specific polysaccharides of Shigella dysenteriae, Shiga; Shigella dysenteriae, Flexner Y; Pneumococcus Type II; and the tubercle bacillus. At the time a study of the relationship of this organism was not proceeded with as it was felt that its morphological peculiarities deserved closer attention than it was then possible to devote ;o them. The organism was provisionally referred to as a Myxococcus, a designation which was based solely on its microscopic appearance. Strained in vivo with a dilute solution of methylene blue it resembles the coccoid stage of many myxococci as depicted by Krzemieniewsey (1928), and incidentally of Spirochaeta cytophaga as described by Hutchinson and Clayton (1919), an organism which Kremienewska (1930) states approaches the myxococci in its characters. Figure 1 shows the polysaccharide-decomposing organism stained in vivo with dilute methylene blue. Its apparently thick-walled coccoid cells contain deeply staining plasmatic inclusions which, in many cases, appear to adhere to one side of the cell wall. The cells measure between 2.5 and 3 1u in diameter; a few may exceed 3 gu and some, not including those attached to larger cells, may be no more than 2 gu in diameter. In the production of smaller coccoid cells by normally sized spheres the organism differs strikingly from the coccoid stage of the myxococci. These attached smaller coccoid cells can be seen to be