Vi] GENERAL CHARACTERS OF BACTERIA log 



logical as well as the experimental test — e.g., typhoid fever 

 bacillus, bacillus of glanders, of diphtheria, of fowl cholera, 

 of fowl enteritis, and many others. So far as actual demon- 

 stration is concerned no other mode of spore formation can 

 be accepted at present. A mode of formation of spores is 

 described by Hueppe to occur in certain spirilla, according 

 to whom the comma-shaped elements and the spirilla form 

 special aggregations of protoplasm in the shape of terminal 

 granules, to which the value of spores is ascribed, and which 

 are called arthro-spores. But the evidence and proof for 

 this is quite unsatisfactory, and, judging these appearances 

 in the light of the character of well-ascertained spores of 

 other bacilli, they are contrary to the assumption of spores. 

 These arthro-spores of Hueppe do not look like spores, do 

 not behave in staining like spores, and do not behave in 

 drying and heating experiments like spores. In the first 

 place they do not differ in aspect from ordinary protoplas- 

 mic granules observable in some of these bacilli under all 

 conditions ; they stain in the ordinary dyes and after the 

 ordinary methods like the ordinary protoplasmic contents of 

 bacteria ; and they are killed by drying and exposure to 60° 

 C. for five minutes. 



It can be easily shown that artificial cultures of these 

 comma bacilli growing under conditions very favourable 

 for the formation of real spores in other bacilli — e.g., a good 

 supply of oxygen, temperature, soil, and moisture — contain 

 after some weeks and months those granules or supposed 

 arthrospores in enormous numbers ; in fact, there is almost 

 nothing else left, and yet no subcultures can be established 

 from such a culture, it being barren of all life. Structures have 

 been described also in the typhoid bacilli as occurring in 

 potato cultures, which can be, however, shown by special 

 modes of staining to be different from real spores, and the 



