A STUDY OF THE MICROBES OF PDS. 
719- 
entrance into circulation, septicaemia and death follow. The 
aureus was isolated from two other cases in the course of my 
studies, from a deep seated abscess on the neck of a horse and 
from a boil on a student’s face.. 
Staphylococcus Pyogenes var. Citreus.— August 12, 
inoculated gelatin with pus obtained from fistula immediatelv 
after being lanced. August 14, a minute white growth on 
surface on track of needle. August 16. growth extended all 
over surface of gelatin, which was partially liquefied. August 
17, gelatin wholly liquefied and a white sediment on bottom 
of tube ; inoculated bouillon from gelatin culture. August 18, 
a number of white colonies were visible throughout the bouil¬ 
lon, which consequently had a turbid appearance. August 
19, inoculated agar-agar from gelatin. August 20, a white 
growth developed along track of needle and at point of in¬ 
oculation. August 21, growth about one-quarter inch in di¬ 
ameter and arranged in radiating circles, the inner circle of a 
darker color than those at outer part of growth. Microsco¬ 
pical examination showed it to be around organism, arranged 
in little bunches sometimes slightly chained or singly. Au¬ 
gust 21, inoculated sterilized potato in tube. August 22, a 
small white growth at point of inoculation ; by the 23d this 
growth had developed over one-third the surface of the pota¬ 
to, and was arranged in radiating circles, each external ring 
being of a lighter yellow hue, as on agar-agar. On the 24th 
inoculated a mouse. August 26, a small abscess at seat of in¬ 
oculation ; agar-agar inoculation from this abscess produced 
the same characteristic growth previously mentioned. August 
28, mouse found dead. 
Post-mortem examination showed no internal lesions, 
though a round organism was seen on section of the liver under 
the microscope. I failed to get a pure culture of the original 
organism. One rat and two mice were inoculated with this 
germ later on. An abscess developed at seat of inoculation 
in one of the mice and the other died. No lesions were pre¬ 
sented on making a post-mortem examination, though a pure 
culture of the citreus was isolated from an agar-agar inocula¬ 
tion from the spleen. 
