CHAPTER VI 



GENERAL CHARACTERS OF BACTERIA 



Bacteria are minute organisms not containing chlorophyll, 

 and multiplying by fision — hence the term schizomycetes (v- 

 Nageli). They are composed of a kind of protoplasm, the 

 mycoprotein of Nencki, and are invested with a membrane, 

 which is composed chiefly of cellulose and a certain amount 

 of mycoprotein (Nencki). 



Their contents are transparent and clear, but sometimes 

 contain minute bright granules of sulphur (Beggiatoa). 

 Owing to the cellulose membrane they resist the action of 

 acids and alkalies. Under favourable conditions of growth 

 bacteria are able by rapid multiplication to form colonies ; 

 the individuals are then embedded in a hyaline gelatinous 

 matrix produced by them ; this is also mycoprotein. Some 

 species are possessed of one, two or more straight or wavy 

 or spiral cilia or flagella, and thereby they are capable of 

 locomotion ; some darting through or spinning round in the 

 fluid in which they are suspended. Such is the case with 

 some kinds of bacilli and spirilla as will be described later. 



Bacteria grow best when left undisturbed in the dark ; 

 movement of the vessel in which they grow is not advan- 

 tageous. Light and electricity do not appear to have a 



