APPENDIX A 



A KEY TO THE IDENTIFICATION OF THE COMMON PATHOGENIC 

 AND A FEW OF THE WELL KNOWN SAPEOPHYTIC BACTERIA 



This key has been compiled from the works of Migula and Chester, the 

 latter of which contains a very complete key to practically all known bac- 

 teria. To this, as well as to Migula, Sternberg and Kolle and Wassermann 

 (for the pathogenic bacteria), the student is referred for detailed descriptions 

 of the various organisms. 



Cells in their free condition globular (cocci). 

 A. Cells without flagella. 



I. Division in only one direction of space forming chains (streptococci). 



1. Grow on gelatin. 



a) Do not liquefy gelatin. 



1) No surface growth in gelatin stabs. 



Sir. erysipelatos Fehleisen. 



II. Division in two directions of space (micrococci). 



1. Grow on gelatin. 



a) Colonies white. 



1) Do not liquefy gelatin. 



M. Melitinsis Bruce. 



2) Liquefy gelatin. 



M. pyogenes var. albus ( Eosenbach ) L. & N. 



b) Colonies yellow, and liquefy gelatin. 



M. pyogenes var. awews(Rosenbach)L. & N, 



2. Do not grow on gelatin. 



M . gonorrhoeae (Baum) Fluegge. 

 M. Weichselbaumii (Trevisan). 



III. Division in three directions of space (sarcinae). 

 1. Grow on gelatin. 



a) Colonies white. 



1) Do not liquefy gelatin. 



Sar. tetragena (Gaffky) Mig. 



b) Colonies yellow. 



1) Do not liquefy gelatin. 



Sar. lutea Fluegge. 

 Sar. ventriculi Goodsir. 



2) Liquefy gelatin. 



Sar. aurantiaca Fluegge. 



Cells short or long, cylindrical, straight, without sheath, endospores present 

 or absent, non-motile (bacteria). 



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