no 
Journal of Agricultural Research 
Vol. VIII, No. 3 
The two organisms carried under the name of B. phytophthorus were 
not tested upon milk and litmus milk. 
Litmus milk. —On litmus milk the six organisms mentioned above 
produced at 20° C. a rather slow, moderate acid development at first, 
but later the cultures became strongly acid. At this temperature reduc¬ 
tion or bleaching begins to appear at the end of one month's time. If 
the tubes were then heated sufficiently to kill the organisms, the red 
color promptly returned. 
Gelatin colonies. —Colonies upon gelatin plate cultures made from 
meat-extract broth plus io per cent by weight of Nelson's photographic 
gelatin No. i and made neutral to phenolphthalein, incubated at 20° C. 
were identical in the case of B . atrosepticus , B. solanisaprus , B. melano- 
genes , and the three Maine organisms. These characters were: Growth 
rapid, buried colonies in 24 hours, round, margins entire. Under a 
16-mm. objective and 12 eye-piece, the colonies at this time appeared 
nearly white and finely granular, usually with a faint indication of 
liquefaction at the margin. In 48 hours, in every case, a well-defined 
crateriform liquefaction had appeared and heavily seeded plates would 
be largely liquefied by this time at 20° C. 
Agar colonies. —The organisms mentioned in the preceding para¬ 
graph likewise gave characters identical with each other upon neutral 
meat extract agar. In 24 hours, viewed under a 16-mm. objective and 
6 ocular, the colonies were brownish-yellowish in color, finely granu¬ 
lar, margins entire, lens shaped to slightly ovoid or spherical. Viewed 
under a hand lens the colonies were slightly yellowish in color. The 
surface colonies were pearly white, bluish opalescent to transmitted 
light, flat, circular, and occasionally amoeboid in shape if the plate were 
thinly seeded and the surface moist. 
Some preliminary work was done, but no detailed studies were made 
with regard to the colonies produced upon gelatin and agar with the 
two organisms received and studied as B. phytophthorus . 
Fermi's solution. —In liquid cultures of Fermi's solution all the 
organisms showed a slight clouding in 24 hours. In 48 hours this was 
very well defined, but moderate, in the case of B . atrosepticus , B. solani¬ 
saprus , B . melanogenes , IIIA, SE, and IIP, with a tendency to form a 
pellicle, which in the case of SE was frequently quite well defined. B . 
phytophthorus from Appel and B. phytophthorus from Schuster at the 
same time had produced only a faint trace of cloudiness in the medium 
which later disappeared. Later observations showed considerable in¬ 
crease of cloudiness, almost to opaqueness in the case of the first six 
organisms named. 
Fermi's solution plus agar. —No attempt was made to grow the 
various organisms on Fermi's solution in silicate jelly, but one trial was 
made in which one and one-half per cent of agar was added and the 
sterilized tubes of media, slanted as in ordinary beef-peptone agar. On 
