COMPARATIVE STUDY OF THE COCCI 5 1 



about equal proportions, were recorded in an intermediate 

 class. 



Flagella. In view of the work of Ellis (1902), we 

 devoted considerable time to the study of motility among 

 the cocci. This author reported the finding of spores 

 and flagella in various streptococci and sarcinae, and 

 Arthur Meyer has carried the position of the Marburg 

 bacteriologists to an extreme in the statement that "the 

 researches of Ellis have rendered it doubtful whether 

 there are any species of bacteria which entirely lack 

 flagella" (Meyer, 1903). We examined a number of 

 cultures very carefully, transferring them at frequent 

 intervals on different media, according to the general 

 plan adopted by Ellis. We found in almost every case 

 active vibratory movements, with a tendency to incom- 

 plete rotation, the successive jerks sometimes producing 

 a gradual translation across the field; but never true 

 spontaneous motion. This type of behavior is entirely 

 different from the motility, characterized by slow, steady 

 revolution, which appears in such forms as the M. agilis 

 of Ali-Cohen. We are convinced that most of the cocci 

 are non-motile, while a few forms show true movement, 

 associated with clearly stainable flagella. The study of 

 this character is therefore of significance. It is question- 

 able, however, whether it is not one of the less important 

 characters in this group of bacteria. It appears, from 

 the published descriptions of species, that this property 

 is not correlated with any other character, — arising 



