semi-^olid at 15° C, and is j^erfectly fluid at 18° C. ; i. e., the melting point has been 

 reducecl 6 to S degrees, indicating a partial i>eptonization. 



The most rapid liquefaction obtained was with a streak culture on 

 stock 205. It was inoculated with a large loop from a fluid culture 

 10 days old and was kept at IS" to 24:- C. On the twelfth da\' there 

 was a thin, pale-yellow streak 2 to 3 mm. wide and 5 cm. long, in the 

 middle part of which there was a small hole containing fluid gelatin. 

 This liquefaction began the ninth or tenth day with a slight sinking 

 in of this part of the streak. On the twentieth day the liquefaction 

 involved about one-fourth of the gelatin (10 c. c). On the twent}'- 

 ninth day fully three-fourths of the gelatin was fluid and there was a 

 copious pale-yellow precipitate (temperature since last record, about 

 22^ C). Not until the thirty-ninth day was all of the gelatin fluid. 



All of these gelatins contained some muscle sugar, which may have 

 slightly retarded liquefaction, since various writers have shown for a 

 number of bacteria that small doses of grape sugar retard and large 

 ones prevent liquefaction. 



2X 



In stock 208 (stock 205 ^ enough ^ c. p. HCl to make it neutral 



to sensitive neutral litmus paper) there was no growth whatever at 

 10^ C. This inoculation was a streak the whole length of a long slant. 

 It was made with a large loop of fluid from a beef-broth culture 7 

 days old and well stocked with living germs, as shown by the result of 

 concomitant inoculations into other media. This culture was kept 

 under observation 22 days. Inasmuch as the organism grew well in 

 stock 205. and will also grow at 10^ C. the failure of this tube was 

 ascribed to the sodium chloride developed in the gelatin by the addi- 

 tion of the HCl. enough being produced to give a feeble taste of salt. 

 (See p. 13.) 



In the ^ 20 gelatin (stock 214b) this organism and Ps. phaseoli 

 behaved much alike, both growing very much better than Ps. 

 canqx'Stri^. 



In poured plates (+ 20 gelatin in Petri dishes) the buried colonies 

 were round, roundish, or ellipsoidal, with smooth margins. No spin- 

 dle-shaped colonies were seen and none or few having rough, irregu- 

 lar margins. (See plate cultures under Nutrient Agars.) 



The size of these buried colonies in densely crowded plates (2.000 to 

 3,000 colonies per tield of Zeiss 16 mm. aprochromatic and 12 com- 

 pensating ocular), after 5 days at 13^ to 16^ C, was usually 16 by 16)u 

 or 16 by 20/^. Some, however, were smaller, and others were as large 

 as 21 by 24/^ or even 28 by 32//. The colonies were nearly colorless 

 and very tinely granular, with margin:i sharply detined and free from 

 irregular outgrowths. Occasionally there were queer looking com- 

 pound colonies resulting apparently from the growth of the component 

 members of small zooglceae. The plates were distinctly clouded to the 



