CHAPTER VI. 



MORPHOLOGY OF BACTERIA. 



BACTERIA are minute organisms not containing chlorophyll, 

 and multiplying by fission 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. Many species of bacteria micrococcus, 

 bacterium, spirillum 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 or two straight or slightly 

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

 motion, darting through, or spinning round, in the fluid in 

 which they are suspended. Such is the case with some 

 kinds of bacteria, bacilli, and spirilla. 



Bacteria grow best when left undisturbed ; movement of 

 the vessel in which they grow is not advantageous. Light 

 and electricity do not appear to have a decided influence 

 on some bacteria, since they grow well in the light. Accord- 

 ing to Cohn and Mendelssohn, 1 strong electric currents have 

 a noxious influence on the growth of micrococci. 

 1 Cohn's Beitr. z. Biol d, Pfl. Bd. iii. i. 



