THE CHARACTERISTICS OF PROTEUS AMMONIAE

There is considerable interest at present in the definition of the species com-prising the genus Proteus. Particularly for the clinical bacteriologist, this genus has been a catch-all for strains which did not fit the genus Salmonella or the coliform group. The generic characters of Proteus are distinctive enough, but no agreement has been reached as to the valid species within the genus. In the course of certain studies of gram-negative, non-lactose-fermenting bacteria we have examined 32 strains ' which we identified as Protes ammoniae (Hager and Magath, 1925; Magath, 1928). Two of these strains were kindly furnished us from Magath's collection by Dr. L. Thompson, and may thus be regarded as authentic representatives of the species. The sources of the strains were as follows: Cystoscopic urine samples.................................................. 13 Stool specimens............................................................ 9 Amer. Type Culture Col................................................... 2 Magath's collection........................................................