12 THE STORY OF THE BACTERIA. 



you the character and destiny of some of the 

 lower forms of cells, which we find in the hu- 

 man body, those which have not undergone 

 that differentiation in structure and function 

 which belongs to higher types ; to speak of 

 the marvellous potentialities which are dor- 

 mant in them ; to show you how their very 

 simplicity of existence, the absence of special 

 powers, and their boundless capacity for re- 

 production particularly fit them to become the 

 conservators of the individual ; to indicate 

 what an important role some of them play 

 in the healing of wounds and in the formation 



o 



of new tissues. So we are not to think of the 

 lower forms of cells in the body as insignifi- 

 cant, because under ordinary circumstances 

 their being and performances are humble 

 and inconspicuous, for they seem to be ever 

 ready, either resting quietly in their tiny nooks 

 within the solid tissues, or driven restlessly in 

 the rushing torrent of the blood, to assume 

 again the lowly but active powers of embry- 

 onic cells, and begin when necessary the work 

 of reproduction and repair. 



These cells have, too, a most important role. 



