BACTERIA AS PLANTS. 



are prepared to believe them capable of producing 

 changes wherever they get a foothold and begin 

 to grow. Their power of feeding upon com- 

 plex organic food 

 and producing chemi- 

 cal changes therein, 

 together with their 

 marvellous power of 

 assimilating this ma- 

 terial as food, make 

 them agents in Na- 

 ture of extreme im- FIG. 9. Showing various shaped 

 portance. rods - 



DIFFERENCES BETWEEN DIFFERENT SPECIES OF 

 BACTERIA. 



While bacteria are thus very simple in form, 



there are a few 



(jpj) f^Q) other slight varia- 



tions in detail 



C S^ir^^J C^^\ which assist in dis- 

 tinguishing them. 

 The rods are some- 

 times very blunt at 

 the ends, almost 

 as if cut square 

 across, while in 

 other species they 

 are more rounded 

 and occasionally 



slightlv tapering 

 FIG. 10. Bacteria surrounded by cap- /Tj?L ' \ Qnme 

 sules : a and b represent zooglrea; l, ri &- 9/- * 30 



c, Chains of cocci with a capsule ; times they are sur- 



d, Bacteria showing the supposed rounded bv a thin 

 structure in which x is the nucleus, J 



and y the protoplasm layer of some gelat- 



