Microbic Diseases Individually Considered. 149 



bers on the back of a colt a few weeks old, and 

 which was successfully treated in the college hos- 

 pital. 



The streptococcus pyogenes seems to be also the 

 causative agent in erysipelas and pt^erpera^/euer under 

 its various forms ; at least, the streptococcus of these 

 two diseases can not be satisfactorily diflerentiated 

 from that which we are now considering. 



The streptocooccus pyo- -p. g 



genes is widely distributed 

 and its virulence is subject 

 to great variations; when 

 injected to animals, and es- 

 pecially to the rabbit, it 

 most frequently gives rise • 

 to a local abscess, but it can 

 also, like the staphylococcus 

 pyogenes, occasion multiple 

 abscesses in the muscles, — •** 



kidney, lung, etc., and more Streptococci in pus of closed 



, "^ .^\^■ 1 , abscess of horse. X 1,000.— D. 



or less quickly bring about 



a fatal termination. The staphylococcus aureus is 

 encountered still more frequently than the strepto- 

 coccus. 



Cultures. — The pyogenic germs are easily culti- 

 vated in the different media ; the three staphylococci 

 are distinguished from each other by the color of 

 their cultures, the aureus giving a golden yellow 

 color, the alhus a white color, and the citreus a citron 

 yellow color. 



The staphylococci pyogenes are aerobic ; the strep- 

 tococcus is rather anaerobic. 



The chemical study of cultures of the staphylococ- 



