THE PROPORTION OF VIABLE BACTERIA IN YOUNG 



CULTURES WITH ESPECIAL REFERENCE 



TO THE TECHNIQUE EMPLOYED 



IN COUNTING 



G. S. WILSON 

 From the Institute of Pathology, Charing Cross Hospital, London 



Received for publication December 16, 1921 

 PART I 



During the course of some work on the morphological changes 

 occurring during the life history of certain bacteria, it became 

 desirable to ascertain the true relationship existing between the 

 number of living organisms and the total number of cells in a 

 young broth culture. A few preliminary experiments were suf- 

 ficient to show that a certain discrepancy existed between these 

 numbers in spite of the fact that it has been frequently stated, 

 and in many cases taken for granted, that inayoung broth culture 

 — up to twenty-four hours — all the bacilli are viable. On look- 

 ing up the literature it was found that of the many observers who 

 had made a comparison of the two counts — Hehewerth (1901), 

 Zelikow (1906), Eijkman (1904), Winterberg (1898), Hein (1902), 

 Wright (1902), Anderson, Fred and Peterson (1920) and Glynn, 

 Powell, Rees and Cox (1913) — not one had succeeded in proving 

 the two to be identical. In fact, in the majority of cases, a de- 

 finite numerical inferiority was found in the case of the viable 

 count. In nearly every case this discrepancy was passed over with 

 but Uttle comment, the results being explained by errors in the 

 technical procedure adopted. The argument appears to have 

 been that because in the early stage of a bacterial culture all the 

 bacilli are living, then any failure in the agreement of the total 

 and viable counts must be due to technical error. To determine 



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JOUBNAL OP BACTEHIOLOOY, VOL. VII, NO. 1 



