194 MICROBIOLOGY 



pathogenic powers for experimental animals are constantly 

 present and seem to stand in a causal relation to the disease, 

 the pathologist is confronted with a puzzling problem in trying 

 to determine the source and the etiological importance of the 

 organism in hand. In cases of infection leading at once to 

 septicemia, peritonitis or suppuration, the explanation is more 



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4. S. 6. 



Fig. 45. Six forms of streptococci. 1. Long chains consisting of 

 small segments arranged with equal spaces between them. 2. Long 

 and shorter chains in which the segments are arranged in pairs. 

 The size of the individual segments is considerable larger than those 

 in the long chains. 3. Short and longer chains where the segments 

 are oval with the long diameter perpendicular to the long axis of the 

 chain. 4. Long interlacing chains. 5. Short and longer chains with 

 one or more segments very much larger than the others. 6. Chains 

 showing divisions in two planes. This form of division has been 

 observed in a few cases. The dividing in two planes is an exception 

 which is not satisfactorily explained. X about 1000. 



simple than in the epizootic diseases, such as Brustseuche, 

 where the constant presence of streptococci in the lesions can 

 be quite as easily explained on the ground of their invasions of 

 the parts affected from a normal habitat as on the hypothesis 



