22 



THE NATURE OF BACTERIA. 



attached they form irregular masses (Fig. 6, b). In a third 

 type the divisions are in the three planes of space at right 



FIG. 6. 







n 

 



> ^> 



Cocci or spherical bacteria : a, Streptococcus ; b, Micrococcus ; c, Sarcina. 



angles to each other (Fig. 6, c). In such cases there result 

 solid masses of fours or some multiples of four. In accord- 

 ance .with these methods of division the cocci are divided as 

 follows : 



Streptococcus. Division in one plane only, frequently 

 forming chains (Fig. 6, a). 



Micrococcus. Divisions in two planes, the spheres either 

 separate or forming irregular masses (Fig. 6, b). When 

 forming masses they are sometimes called Staphylococcus 

 and when in twos occasionally called Diplococcus. These 

 terms are going out of use. 



Sarcina. Divisions in three planes, forming solid masses 

 in groups of four or multiples of four (Fig. 6, c). 



