22 The Colorado Experiment' Station 
solution, and for maltose with Fehling’s solution. Starch was 
present at all times, and at no time was there any reduction of 
the Fehling’s solution; therefore no diastase was formed. 
INVERTASE.—Saccharose broth, prepared by adding 1 % of 
saccharose to sugar free broth, was used in the determination 
of invertase. 100 c.c. of this medium were inoculated and after 
five, seven and thirty days tests were made for invert sugar with 
Fehling’s solution. There was no reduction at the end of five 
days, a slight one after seven days and at the end of thirty days, 
a good test for glucose was obtained from the inoculated flask, 
while the sterile control gave no reduction of the Fehling’s sol¬ 
ution; therefore invertase was formed. 
ZYMASE.—Glucose broth, prepared by adding 1 % of glucose 
to sugar free broth, was used in our study of zymase. Observa¬ 
tions covering a period of thirty days failed to show at any time 
the evolution of CO, gas, or the presence of alcohol in the in¬ 
oculated tubes, and consequently, we have concluded that there 
was no zymase produced. 
RENNET.—Plain milk was employed as the medium in the 
study of rennet production. At no time during the thirty day 
period of examination, did the inoculated milk tubes show any 
evidence of curd formation, which fact has been interpreted as 
indicating the absence of rennet. 
PEPSIN.—Plain milk and nutrient gelatin, contained in test 
tubes, were epmloyed as the media in the study of pepsin forma¬ 
tion. Stab cultures were made in the gelatin and the milk was 
inoculated in the usual way. There was neither any liquefac¬ 
tion of the gelatin nor any digestion of the casein of the milk 
during the period of observation, which was sixty days for the 
gelatin and forty days for the milk. 
GLUCASE.—Beer wort, and sugar free broth to which 1% 
of maltose was added, furnished the media for the study of glu- 
case, but owing to the difficulty in distinguishing maltose from 
glucase when present in the same solution, no satisfactory con¬ 
clusions could be reached regarding the presence of glucase, and 
hence concerning the production of glucase. 
16. Crystals Formed. 
No crystals have been observed to form in any of the media 
employed. 
IV. PATHOGENICITY 
1. Pathogenic to Animals. 
Inasmuch as the organism does not grow at 37 % ° C. it has 
been considered unnecessary to carry on any animal inoculations. 
2. Pathogenic to Plants. 
Pathogenic for alfalfa (Medicago sativa) ; not pathogenic under 
field conditions for sweet clover (Melilotus alba), white clover 
(Trifoliunx repens), or winter vetch (Vicia sativa). 
V. NUMERICAL CLASSIFICATION 
According to the numerical system of recording the salient 
characters of an organism, Ps. medicaginis, n. sp. (Sackett) be¬ 
comes Ps. 212.3332133. 
MEDIA EMPLOYED. 
The nutrient broth, nutrient gelatin, nutrient agar and sugar 
]ree broth, employed in this work, have been prepared according to 
the Standard Methods of Water Analysis (i ). Reaction -{- 15 ° Ful¬ 
ler’s scale. 
