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PUBLIC HEALTH BACTERIOLOGY 



glycerin egg in the first few generations are of the bovine 

 type. 



Glycerin egg (Lubenau). Ten eggs are blown into a flask and 200 c.c. 

 of 5 per cent glycerin bouillon (neutral or moderately alkaline) added. 

 The further preparation is as for plain egg medium. 



3. RESULTS. 



TABLE OF SERIES OF NON-SELECTED CASES OF EVERY TYPE OF 

 THE DISEASE, SHOWING TYPE OF BACILLUS ISOLATED. 



4. CONCLUSIONS (Park and Krurmviede) loc. cit. p. 134. 



Tubercle bacilli as isolated from man fall into two groups. 

 One of these groups is identical in all its characters with that 

 found in cattle. That is, all tubercle bacilli from man and 

 cattle fall into two groups, which have been designated the 

 human and bovine types. 



Each type shows certain differences, the most important 

 for separation being those culturally and in virulence. The 

 great majority of cultures group themselves around two 

 extremes, from which there are a few cultures showing variant 

 characteristics. There is no overlapping of characteristics. 

 The two types are probably different because of residence in 

 different hosts over long periods of time, and as such are 

 stable. The evidence in favour of rapid change of type is 

 incomplete and inconclusive. 



* Includes i double infection : Mesenteric nodes gave human type, 

 meningeal fluid gave bovine type. 



