112 A MANUAL OF BACTERIOLOGY 



Cladothrix, which shows coccus, rod, thread, and 

 spirillar forms. 



Baumgarten divides microbes into two groups, 

 each containing three genera : 



The genus Bacterium is entirely dispensed with in 

 this classification ; and Fliigge, who modified Cohn's 

 classification, has submerged the genus Bacterium 

 into the genus Bacillus, as both these forms were 

 rod-shaped ; but it should be borne in mind that 

 the bacteria do not produce spores, whereas in 

 the bacilli spore-formation is of common occur- 

 rence. 



Hueppe's classification is based on the mode of 

 reproduction, or, rather, fructification ; and the late 

 Dr. De Bary divided them into two groups : Mic- 

 robes which produce endospores, and microbes 

 which produce arthrospores. But as we know so 

 little about spore-formation in the Schizomycetes, 

 Hueppe's and De Bary's classifications are of very 

 little practical value at the present time. 



'The determination of species rests upon the 

 accumulated evidence afforded by a thorough know- 

 ledge of their life-history.' The form of the mic- 

 robe, the physiological, pathological, and other 



