GENERAL SYSTEMATIC BACTERIOLOGY 199 



This is the first definite inclusion of the character of spore production 

 in the generic diagnosis, but this should not be emphasized as a differ- 

 ential character, for in the description of Bacterium there is the state- 

 ment "Sporenbildung ahnlich wie bei Bacillus." 



Luerssen (1879, p. 22) accepted Cohn's classification practically 

 without modification. Emphasis is placed upon the occurrence of the 

 organism in jointed threads, and no mention is made of sporulation. 

 Magnin (1880, p. 87) used the same description. 



De Bary (1884) influenced largely by the idea of bacterial pleomor- 

 phism, abandoned the old genus Bacterium and put all endosporous rods 

 into the genus Bacillus and all arthrosporous rods and those for which 

 no spores are known into Arthrohacterium. De Bary states: (trans- 

 lation by Garnsey and Balfour 1887, p. 460) 



The forms included under this term (endosporous bacteria) are chiefly known 

 in the growth-form of single rods consisting of one or a few cells, or of rods joined 

 together and forming long filaments; they may also be collected together into 

 larger gelatinous masses or membranes. In some forms the rods are spirally 

 twisted, and these I name here Spirillum of Van Tieghem. Others do not show 

 these curvatures, but are either straight or very slightly bent, all these I include 

 under the term Bacillus and place under that genus all the endosporous forms 

 which have been hitherto known either as Bacillus or as Clostridium, Bacteridiwn, 

 Vibrio, or by some other name. All non-endosporous forms bearing these names 

 on account of their growth form are, of course, excluded from the group. 



It will be noted that this is a direct abandonment of the generic 

 conception of Cohn although the type species may well be said still to be 

 B. suhtilis. 



Van Tieghem (1884, p. 1110) uses the term Bacillus as a form group 

 to include those rods which are not associated but are united into fila- 

 ments of greater or less length, practically in the sense of Cohn. Grove 

 (1884, p. 26) follows Winter minutely. Trevisan (1885, p. 94) included 

 in this genus those organisms showing three stages of development, as 

 rods, filaments and cocci. In the rod or bacillus stage the cells are 

 normally cylindric, or ellipsoid, straight or slightly curved, jointed or not, 

 colorless or colored, cytoplasm equally distributed. Spores single in the 

 rods. Filaments and cocci transitorj^ stages. He included descrip- 

 tions of thirty-one species, the first one described being Bacillus 

 anthracis Cohn. The views of Van Tieghem were in part accepted bj^ 

 Zopf in the third edition of "Die Spaltpilze" (1885, p. 61). In previous 

 editions the term Bacillus was regarded merely as the designation of a 

 growth form of a Bacterium. His diagnosis in the third edition is: 



