CHAPTER II 

 BIOLOGY OF PNEUMOCOCCUS 



The morphology of Pneumococcus in tissues and in cultures; iso- 

 lation, cultivation, and preservation; viability and fragility, and 

 sensitiveness to bile, soaps, and other chemical substances. 



For the student of Pneumococcus there is no lack of reliable de- 

 scriptions of its general or detailed biological features. In or- 

 der, however, that the student may not be obliged to go beyond the 

 covers of this volume for information about the organism, its inti- 

 mate features will be presented here. The more important points 

 have been freely taken from the clearest and most accurate ac- 

 counts in current text and reference books, and acknowledgement 

 is made to the respective authors.* 



Morphology 



The anatomy of Pneumococcus is simple and distinctive. It is 

 best studied in preparations made from body fluids of man or ani- 

 mals suffering from infection. Next best are young, vigorous cul- 

 tures grown on proper culture media containing blood, serum, or 

 other body fluids. When typical, the organism consists of a pair of 

 oval or lance-shaped cocci, their somewhat flattened proximal ends 

 in apposition and their distal portion pointed. Sometimes single 

 cocci are seen, while at other times single or paired cocci may be 

 arranged in short or even long chains, resembling a string of beads 

 — the chapelet originally described by Pasteur. There may be 

 many variations from this characteristic form even when the envi- 

 ronment is favorable. The individual cocci may be round and of 



* The sources consulted, besides original papers, are the article by Neufeld 

 and Schnitzer in the third edition of the Kolle-Kraus-Uhlenhuth Handbuch der 

 Pathogenen Mikroorganismen;?* Zinsser and Bayne-Jones, Textbook of Bac- 

 teriology ,1579 Acute Lobar Pneumonia (Rockefeller Institute Monograph, 

 No. 736) ; and A British System of Bacteriology in Relation to Medicine^ 



