s 



BACTERIOLOGY 



teria, Fig. 4, a; rods, in which the length exceeds the diameter, 

 Fig. 4, b-d; filaments, greatly elongated rods, Fig. 4, e; commas 

 or curved rods, Fig. 4,/,- spirals or serpentine forms. Fig. 4,g, h, t. 

 Rods may be still further divided into ovals, in which the 

 length scarcely exceeds the diameter, Fig. 4, b; short rods, in 

 which the length is 2-4 times the diameter. Fig. 4, c; and long 

 rods, in which the length is 4-8 times the diameter. Fig. 4, d. 



U 



Fig. 4. — Showing forms and grouping of bacteria. 



■a cocci, b ovals, c short rods, d long rods, e filaments, / commas, g short spiral, ht long 

 spiral, i Clostridium forms, k cuneate forms, s clavate forms, m capitate forms, n strep- 

 tobacilli, o streptococci, s diplococci, q staphylococci, r tetrads,^ slreptospirilli, w sarcina. 



Spirals may also be divided in short spirals, the wave spiral, 

 Fig. A^ g ; ^nd long spirals, which are multiples of the former, 

 Fig. 4, h and t. 



Special forms may also be noted which commonly appear 

 ■during sporulation and as involution forms. These are : Clos- 

 tridium forms, or rods swollen in the centre and attenuated at 

 both ends. Fig. 4, i; cuneate forms, wedge-shaped, enlarged 

 at one end and gradually tapering toward the other, Fig. 4, k ; 

 clavate forms, as in Fig. 4, s ; and capitate forms, as in Fig. 4, k. 



