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IOWA ACADEMY OP SCIENCES. 
and rats. Old cultures, however, soon loose their virulence. 
A culture nine months old failed to cause any lesions in mice, 
not even the local formation of pus. 
St. pyogenes, Ogston var. ciireus Passet. — This species has 
not been found spontaneously in any of the cases of pus 
studied, though it has been cultivated in the laboratory. 
It has been included with the pyogenic cocci because of its 
occurrence in pus. Passet found the organism in the pus of 
an acute abscess and Sternberg* says: “As to its pathogenic 
properties, we have no definite information. It is included 
among the pyogenic bacteria because of occasional presence in 
the pus of acute abscesses, although it has heretofore only been 
found in association with other micro-organisms.” Mice have 
been inoculated here at Ames but in no case did fatal sep- 
ticaemia follow. We have, however, had no trouble in obtain- 
ing pus at the point of inoculation under the root of the tail. 
From this pus, pure cultures of the organisms were obtained. 
St. ptyogenes Ogston var., fiavescens Trev. — Obtained from the 
fistula of a horse by Dr. S. Whitbeck in bacteriological labora- 
tory, Iowa Agricultural college. This organism does not 
differ from the foregoing in size; in color, however, it is much 
paler, being an ochre yellow. It produces fatal septicaemia in 
mice when fresh cultures were used, but in this case pure 
cultures were not obtained. 
Streptococcus cinnabar eus, Flugge. — Obtained at first from 
butter, but probably came either from the air or water. Color 
in different media is quite constant, except in blood serum, 
where its color is much paler. It grows quite characteristic 
on the surface of bouillon, forming spherical masses paler than 
in agar or potato. A nearly related species was isolated by 
Dr. W. B. Niles from the heart of a diseased steer affected with 
corn-stalk disease. It differs from the cinnabarcus in the 
change of color. It is dark lemon- yellow at first, and then 
changes to a brick-red. This species will be described in 
another connection. 
Sarcina lutea Schroter. — This well known organism occurs 
chiefiy in the air. Gelatin and agar plates exposed to the air 
invariably show this organism. It comes up somewhat more 
tardily than the non-chromogenic species. They appear as 
small, yellow, spherical colonies. The canary-yellow growth 
liquefies gelatin quite slowly. The same organism has been 
^Manual of Bacteriology p. 273. 
