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 Spirilwm, which attain a 
length of 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 w, in diameter; length 3 
to 4 p. 
Bacterium termo, breadth 0.6 to 0.8 w; length 2 
to 3 pw. 
Vibrio lineola, breadth 0.5 to 1 w; length 38 to 8 pu. 
Bacillus ulna, 55. Wek bo Bs), (3) se eoe 
B. anthracis, jo he (0. 2 wean 5) 20 to ie 
Spirillumvolutans, y, ips ». Ddoadge 
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). 
