1 Q form or conical, branching or not, cross-barred or not, with 

 or without polar granules. The alphabet had been called upon 

 to designate them and particular types had been regarded as 

 so characteristic as to identify the organism. Said Wherry: 

 "The partial tension cultures showed much more luxuriant 

 growth than the aerobic . . . Bringing the bacteria out of 

 the tissues at partial tension enabled them to grow faster and 

 they went on to the formation of barred types, whereas aerobic 

 cultivation yielded chiefly the small, solid staining type." Thus 

 was explained "the occurrence of various morphologic types 

 of the diphtheria bacillus in a mixed culture from the lesions 

 of diphtheria." It could be understood "only when one appre- 

 ciates the influence of oxygen on the rate of growth." Then, 

 as indicative of how clearly he saw the whole problem in 

 nature, he concluded: "In mixed cultures from the throat the 

 morphology ... is probably modified by chemical products 

 of growth as well as by the reduced oxygen tension resulting 

 from such association." 



