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 

 portance. 



im- 



FIG. 9. Showing various shaped 

 rods. 



DIFFERENCES BETWEEN DIFFERENT SPECIES OF 

 BACTERIA. 



While bacteria are thus very simple in form, 



there are a few 

 other slight varia- 

 tions in detail 

 which assist in dis- 

 (a 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 



slightly tapering 

 FIG. 10. Bacteria surrounded by cap- /T?-_ * \ o~ *T 

 sules: a and b represent zoogloea; l ri g- 9)- SOme- 



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



d, Bacteria showing the supposed roun( ied by a thin 

 structure in which x is the nucleus, , r > . 



and y the protoplasm. layer or some gelat- 



