202 r °ki ca ^y ne got hardly any. For the bacterium from the knee 

 joint he got growth neither aerobically nor anaerobically but 

 "thousands" in the intermediate zone; for his Leptothrix 

 (isolated from the human gum line) he got no growth aero- 

 bically, some anaerobically but best growth at partial tension. 

 In the last named instance he had not only shown that partial 

 tension was optimal for the growth of the microorganism but 

 had actually cultivated it for the first time ; on which account 

 he made of his findings a separate paper [5 5]. 



A "discussion" brought these laboratory experiences to a 

 close. Such "theory" of disease as he expounded is rarely 

 read, in consequence is hardly known. Wherefore it is too fre- 

 quently disparaged; what is worse for a sick world, unap- 

 plied. "The majority of bacteria actively multiplying within 

 the tissues of a host are adapted to a pressure of less than 2 1 % 

 oxygen. They exist under partial-oxygen tension," he said. 

 ". . . What effect this observation may have on the cultiva- 

 tion of hitherto unrecognized infectious agents remains to be 

 seen. . . . The fact that B typhosus failed to attack glucose 

 under partial tension but attacked it vigorously when grown 

 aerobically is certainly worth considering. ... Is it not pos- 

 sible that the partial- tension mode of nutrition in vitro is more 

 nearly that which the microorganism follows in the body of 

 the host? If so, does failure to take this into consideration 

 account for our inability to recognize toxine-production by 

 many species in vitro} Does this mode of nutrition build up a 

 bacterial cell body of very different chemical composition 

 from the ordinary aerobic and anaerobic strains we have 

 worked with in the past?" 



He ended with reference to the work of Bordet, Rowland, 

 Rosenow and Beijerinck supportive of his views. He was back 

 in the very fundamentals of biological existence — the drama 

 of life living on life, and the "variations" assumed by species 

 as the conditions for the battle were changed. In conclusion 

 he quoted Beijerinck: "Variations in oxygen pressure above or 

 below that most favorable to vital function are chief factor, 

 and these ferments [Beijerinck used the term in Pasteur's sense, 

 as synonym for microorganisms] only continue to display 

 constant specific characters when continuously cultivated at 



