104 



BACTERIA, YEASTS, AND MOLDS 



the presence or absence of these motor hairs. They 



are known by the name of flagella. 



Spherical Bacteria: Cocci. 

 The simplest type of bac- 

 teria consists of those that 

 are in the shape of a minute 

 sphere. Their size differs 

 somewhat, but they are 

 always extremely minute, and 

 about all that can be said in 

 regard to them is that they 

 are spherical organisms, 

 sometimes possessing flagella 

 and sometimes apparently 



FIG. 48. Cocci, bacilli, and bac- without them. No internal 

 teria. a (Coccus), b and c (Badi- structure is known. They 



/us), show flagella ; d(Bacterium) mu ltiply sometimes in SUCh 



** 



has no flagella. 



a way as Q OQ 

 



to produce long chains (Fig. 49, a), 



sometimes so as to produce groups of a( 



fours or groups of eight or sixteen ^^ 



(Fig. 49, b, c, d). The general name fcp 



given to spherical bacteria is coccus, and 



to this name are sometimes prefixed FlG " 49 ' Cocci > show - 



ing methods of mul- 



certam other syllables to indicate certain tiplication. a, strep- 

 characters. Streptococcus is a name tococcus; b, Micro- 

 given to cocci forming chains (Fig. 49, 

 a), and Micrococcns to those forming 

 fours or irregular masses as at b. The term Sarcina is 

 the name given to those that form solid masses such as 

 shown in Fig. 49, c and d. 



coccus; c and 

 Sarcina. 



