The endospore of Bacillus polymyxa.

The endospore of Bacillus polymyxa was originally described by Meyer (1897) in a study of a bacillus which he designated Astasia asterospora. Meyer's drawings of the spore, showing ridges and the star shaped aspect, were reproduced by Knaysi (1951) over the name Bacillus asterosporus. It has not been generally recognized that this name is synonymous with B. polymyxa (Smith, et al., 1952). So thorough were Meyer's light microscope studies on the morphology, development, sporulation, germination, and cytochemistry of this organism that little need be added to them; however, the electron microscope and the ultramicrotome have given us a better picture of the finer structure of the endospore than was available to Meyer.