66 BACTERIOLOGY 



88.3 per cent., albumin 7.6 per cent., ash 3.6 per cent. The 

 dry substance of the bacteria contains the following : albumin 

 65 per cent., ash 31 per cent. From 76 to 80 per cent, of 

 the ash consists of sodium chloride and phosphate. 



Morphology of Bacteria. For the purposes of this book it 

 will suffice to classify the bacteria roughly into three mor- 

 phological groups with their subdivisions, the members of 

 each group being identified by their individual outline, viz., 

 that of a sphere, a rod, or a spiral. 1 To these three grand 



FIG. 2 



c d e 



a, staphylococci; b, streptococci; c, diplococci; d, tetrads; e, sarcinse. 



divisions are given the names cocci or micrococci, bacilli, 

 and spirilla. 



Mode of Multiplication. In the group micrococci belong 

 all spherical forms i. e., all those forms the isolated individ- 

 ual members of which are practically of the same diameter 

 in all directions. (See Fig. 2, a, 6, c, d, e.) 



The bacilli comprise all oval or rod-formed bacteria. (See 

 Fig. 3.) 



1 For complete data on classification see Reports of Committee of Am. 

 Bact. Soc., Jour. Bact., 1917, vol. ii; 1920, vol. iii. 



