114 PRINCIPLES OF VETERINARY SUROERY 



smearing a drop of pus over gelatin or agar- agar. The sub- 

 sequent cultivation will bring out colonies that are recog- 

 nized from other forms by their orange color. Other cocci 

 may produce every intermediate color between white and 

 yellow, and thus prove confusing. This feature of the cul- 

 tures has often led to the belief that the staphylococcus 

 pyogenes albus is but a non-chromogenic form of the same 

 species. 



Staining. — The organism stains brilliantly with aniline 

 solutions and by Gram's method. 





Fig. 6. 

 Staphylococcus Pyogenes Aureus from Pus. 



Pathogenicity. — The staphylococcus pyogenes aureus 

 may be appropriately designated as a deadly organism, al- 

 though at times it may only cause a rather trivial suppura- 

 tion. When injected subcutaneously it will promptly cause 

 a collection of pus^ and not infrequently it generalizes and 

 causes fatal septic?emia. If the resisting powers of the body 

 are sufficient a sub-acute purulent infection — pyaemia — may 

 result. The golden coccus is more deadly to animals 

 than to man. In the former, especially in the debilitated, 

 fatal generalization is quite certain from any prolonged and 

 active suppuration. The most common cause of death is 

 embolic pneumonia. Coagula containing them, loosen from 



