528 HILDA HEMPL HELLER 



given to motility seems to us to constitute a peculiar infelicity 

 in these schemes." And Winslow and Winslow (1908, p. 52) 

 do not find motility correlated with other characters in the 

 group of the Coccaceae. It would seem that for our purposes 

 the character of motility was entirely unsuited for the making 

 of major divisions. Thus organisms in general so similar as 

 B. Welchii and B. Chauvoei were placed by Migula's system in 

 entirely different groups because one was flagellate and the 

 other was not. And aerobes of many sorts and proteolytic 

 anaerobes dwell in his work peacefully side by side with B. 

 Chauvoei in the enormous and unwieldy genus Bacillus; while 

 B. Welchii on account of its nudity is relegated to the genus 

 Bacterium along with Bacterium tuberculosis and other strangers. 



Spore formation has been turned to by many classifiers as 

 an important character for the subdivisioli of the rod-like forms. 

 Zopf, Kruse, Fischer, Lehmann and Neumann, the Committee, 

 and Breed, Conn, and Baker have used it as a basis for making 

 their primary division. It is probable that this is a character 

 of far more value than is motility. It is, however, true that, 

 though there are many similarities between the sporulating 

 rods, we have no proof that they are more closely related to 

 each other than they are to some of the non-sporulating rods, 

 or that the formation of spores originated with any one type. 

 Should we accept such a hypothesis, we should still be unable 

 to show that certain sporulating rods had not lost their power 

 of spore-formation. This power is certainly an advantage to a 

 species, and on that account anaerobic forms losing it are not so 

 Ukely to persist as are others. But that does not mean that 

 such a phenomenon may not occur. 



Kruse strenuously protests (1896, p. 81) the use of spore- 

 formation as a primary character. Moreover the adoption of 

 spore-formation as a character for the subdivision of the rods 

 would make us exclude from the anaerobic group such organisms 

 as B. egens, B. necrophorus, Bacillus D of Adamson, B. fragilis 

 of Veillon and Zuber, and probably a goodly number of unde- 

 scribed organisms which in their behavior closely resemble the 

 sporulating anaerobes. I find that B. egens and another Gram- 



