198 GENERAL SYSTEMATIC BACTERIOLOGY 



Bacillopsis. A generic name suggested by Petschenko (1908, p. 359) 

 for an organism questionably bacterial. Enlows (1920, p. 19) states: 



Type species (monotypy). B. stylopygae. Found in the digestive tube of 

 Blatta orientalis {Stylopyga orientalis). Length 10m, by 2.5/* wide. A slightly 

 curved rod, with one end slightly pointed, the other obtuse. Nucleus is present. 

 Also highly refractive "corpuscules" in the transparent protoplasm, which are 

 probably nutritive substances. Reproduction by a sort of budding, in which the 

 very small daughter cell remains attached to the mother cell by a delicate fila- 

 ment until it has attained the size of mother cell. After this stage of active 

 growth there is a stage in which filiform prolongations appear, and the "corpus- 

 cules" unite into 1 or 2, rarely 3 large round bodies. Vacuoles observed. In 

 doubt as to position of organism, but does not think it belongs with the bacteria. 

 (Has been included by other authors among the bacteria.) 



Bacillus. A generic name established bj^ Cohn (1872, p. 174) to 

 include three species of rod-shaped organisms, Bacillus subtilis, B. 

 ulna and B. anthracis. He included in this genus those rod-shaped or- 

 ganisms that grow in filaments. The type of the genus was B. subtilis. 

 A discussion by Cohn of spore production in Bacillus subtilis embodied 

 the first accurate description of endospores. His inclusion of the 

 anthrax organism indicates that in his conception of the genus motility 

 was an unimportant characteristic. In a later paper, Cohn (1875, 

 p. 141) included the genus Bacillus under the tribe Nematogenes and 

 characterized it as follows : 



Cells disposed in filaments, filaments not branched, free or interlaced, cylin- 

 drical, colorless, articulations not very distinct, very slender and short. 



It will be noted that in the preceding description emphasis is placed 

 upon the occurrence of the rods in short chains or filaments. Sporula- 

 tion and motility were not included in the generic diagnosis. Within 

 the genus were listed both motile and non-motile forms. Sporulation 

 was discussed in certain of these species, but not rated definitely as a 

 generic character. These facts are emphasized because subsequent 

 generic designations frequently stress other characteristics. 



Winter (1880, p. 38) uses the genus practically in the sense of Cohn. 

 He states: 



Zellen verliingert cylindrische, fast stets in geraden, stielrunden (nicht oder 

 wenig eingeschniirten) Reihen oder Fiiden zusammenhangend, durch Querthei- 

 lung sich vermehrend. Sie bilden Zoogloeen, kommen aber oft auch in dichten 

 Schwarmen (ohne Gallertausscheidung) vereinigt vor. Fortpflanzung durch 

 Sporen. 



