204 GENERAL SYSTEMATIC BACTERIOLOGY 



3. Bacillus. Rods motile by means of peritrichous flagellla. Migula 

 (1895, 1897, 1904), Chester (1901), Kendall (1901), A. J. Smith (1902), 

 E. F. Smith (1905), Ellis (1909), Frost (1911), Schneider (1912). 



4. Bacillus. Non-motile rods, cylindrical, producing endospores. 

 Fischer (1895, 1903), Lotsy (1907). 



5. Bacillus. Any rod-shaped organism. Baumgarten (1890), Stern- 

 berg (1892), Mace (1897), Hewlett (1898), Matzuschita (1902). 



6. Bacillus. Any motile rod. Conn (1909). 



It would seem that the genus name Bacillus should be retained for 

 the designation of a limited group of organisms, though probably 

 no harm can come from the use of the term bacillus as a casual name to 

 indicate rod-shaped organisms in general. It should be emphasized 

 that when used as a generic designation it is a proper noun, and must be 

 capitalized, whenever used. Many bacteriologists have ignored this 

 rule which is followed so carefully by systematists and biologists in 

 treating all other forms of life. Vuillemin's contention that the use of 

 bacillus as a vulgar noun leads to confusion is not well premised. The 

 genus Aster is universally recognized by botanists as valid. This does 

 not interfere with the use and usefulness of the common name aster 

 which includes many species not belonging to the genus Aster. By no 

 means all of the plants commonly known as lilies are placed by the botan- 

 ist in the genus Lilium. There is no reason why we cannot continue 

 to speak of the tubercle bacillus even though it does not belong to the 

 bacterial genus Bacillus. 



In some form or with some definition the genus Bacillus should be 

 retained. The type practically always accepted is B. subtilis. The 

 definition of Fischer should therefore be abandoned as including only 

 non-motile forms. He would exclude from the genus its first described 

 species. The original description of Cohn is scarcely suflScient, for 

 much stress was laid upon cell grouping and length of cell and not upon 

 other characters. The use of Migula's diagnosis, including in the genus 

 all rods with peritrichous flagella, is the cause of great confusion. It 

 brings into the genus such discordant types as the hay bacillus and the 

 typhoid bacillus. It excludes from the genus the anthrax bacillus so 

 closely related to the hay bacillus. It does not result in bringing forms 

 that are closely related together. Migula's definition should be aban- 

 doned as not based upon natural affinities. The definitions which would 

 include aU rods in the genus Bacillus have the merit of simplicity, but 

 when organisms so diverse in characteristics as the tubercle bacillus, 

 the typhoid bacillus, the tetanus bacillus, and the anthrax bacillus, are 



