30 MORPHOLOGY OF THE BACTERIA. 



length and thickness, are comprised within the 

 limits of errors of observation. 



The globular bacteria are the smallest, and the 

 dimensions of some species are so minute that 

 they cannot be measured directly. 



The largest are the Spirillum, which attain a 

 length of y 2 ^- of a millimetre. Between these two 

 extremes, there are all intermediary sizes possible. 

 The dimensions of some of the bacteria are given 

 below: 



Monas vinosa, 0.5 to 1 /-t, in diameter; length 3 

 to4|k 



Bacterium termo, breadth 0.6 to 0.8 ^; length 2 

 to 3/4. 



Vibrio lineola, breadth 0.5 to 1 p ; length 3 to 8 //,. 



Bacillus ulna, 0.7 to 1 /z ; 5 to 8 /it. 



B. anthracis, 1 to 2 //, ; ,,10 to 50 p. 



Spirillumvolutans, 7 /z ; ,,10 to 40 JJL. 



Several authors, considering exclusively this 

 character of dimensions, have divided the monera 

 and the bacteria according to their size. Thus 

 Hoffmann recognizes in addition to the monera, 

 only the microbacteria, the mesobacteria, and the 

 macrobacteria. In the same way Billroth classi- 

 fies the monads according to their dimensions into 

 micro, meso, mega coccos, and the bacteria into 

 micro, meso, mega bacteria. Finally, Klebs sep- 

 arates the Micrococcos from the Microsporines, 

 which do not differ from them except by their 

 smaller dimensions, both forms being able to pass 

 to the state of bacteria (rods). 



