A Study of Variation of Salmonella Pullorum. H. van Roekel. Mass. Experiment Station Bulletin 319, March, 1935, Amherst, Mass.

Summary and Conclusions:

From the experimental evidence obtained in the investigation discussed here the following conclusions seem justified.

Variation of characters of S. pullorum may be detected among freshly isolated strains, as revealed by 13 of 163 strains studied.

The behavior of the recently isolated variants in sodium chloride solution of different concentrations and in the presence of positive and negative sera differed greatly.

Such properties as colonial and cellular morphology, Gram-staining, and biochemical reactions revealed little or no variation in the majority of the derived variants.