How Bacteria are Studied 41 



The nomenclature in bacteriology is still in 

 a rather chaotic condition, but a beginning has 

 been made. The term bacteria (singular, bac- 

 terium) applies to the whole class of organisms 

 of whatever shape. They are also sometimes 

 called " germs," or ' 'mi- 

 crobes," or "micro-organ- 

 isms," which means small 

 living beings. The round 

 or spheroidal form is 

 called ' l coccus, ' ' which 

 means a berry; the plural 

 is cocci. The botanical FIG . 4 ._ STREPTOCOCCI 

 name of the most com- FRO M A CULTURE 

 mon form of the round 

 or spheroidal bacteria is Micrococcus that 

 means "a little berry." Thus there is a 

 species of micrococcus which produces a yel- 

 low color when it is growing in masses. This 

 species is called Micrococcus luteus the yel- 

 low micrococcus. 



Another genus among the spheroidal bac- 

 teria is called Streptococcus "a chain of ber- 

 ries" Fig. 4 because the little balls tend to 

 cling together and form longer and shorter 



