BACTERIOLOGICAL TECHNIQUE 



17 



vegetable life. Under a high-power microscope they appear 

 as minute round dots, rods or threads ; they multiply either by 

 splitting into two (that is, by fission or cell division), or by the 



o 



o o 



o o 



I. BACTERIA. 



IL YEASTS. 



III. MOULDS. 



I A . BEGGIATOA. 



FIG. 3. BACTERIA, YEASTS, MOULDS, AND BEGGIATOA. 



production of small protuberances, which separate eventually 

 from the main organism and develop into fresh organisms 

 similar to the parent organism ; this method of reproduction 

 is known as spore formation. Bacteria are colourless, that k, 



