BACTERIAL CLASSIFICATION 5 



themselves. Organic individuals have not been cre- 

 ated in symmetrical groups differing in the presence 

 or absence of character, A, each group including two 

 subgroups respectively possessing and lacking charac- 

 ter, B. They have been developed by natural laws 

 along irregular and complex lines, and are now related 

 in family groupings of infinitely various kinds and 

 degrees. A paragraph from Hall's monograph of 

 the Composite of California (Hall, 1907) applies to 

 systematic bacteriology even more than to the classi- 

 fication of the higher plants: "A rational system of 

 classification should bring out the natural relationship 

 between the various forms; should, in other words, repre- 

 sent the cleavage of the larger groups into their com- 

 ponent parts as it has taken place in nature. Much of 

 our recent work, however, has unfortunately consisted 

 of a mere cutting across the grain, the result being a 

 mass of chips — the so-called species — each being a 

 purely artificial product and bearing no evident re- 

 lationship to the others. This is commonly the result 

 of hasty work where the perpetrator has been too 

 busy to work out natural affinities through a com- 

 parison of inter-grading forms accompanied by field 

 study." 



Not field study, in the ordinary sense, but painstaking 

 and sympathetic laboratory study of the organisms 

 themselves and their " intergrading forms," is needed to 

 make systematic bacterial relations plain; and the fruit 



