4 BACTERIA IN DAILY LIFE 



a worm or a whale, the work is exclusively per- 

 formed by infinitely small organisms. They are 

 the important, almost the only, agents of universal 

 hygiene ; they clear away more quickly than the 

 dogs of Constantinople or the wild beasts of the 

 desert the remains of all that has had life ; they 

 protect the living against the dead. They do 

 more ; if there are still living beings, if, since the 

 hundreds of centuries the world has been in- 

 habited, life continues, it is to them we owe it." 



Fortunately, the provisions made by Nature for 

 the preservation of the bacterial race are of so 

 lavish a description that no fear need be enter- 

 tained that this useful and indispensable world 

 of life will be wiped out. The fabulous capacity 

 for multiplication possessed by them (a new gene- 

 ration arising in considerably less than an hour), 

 the powers of endurance which some of them 

 exhibit in presence of the most trying vicissi- 

 tudes of heat and cold (they have been known 

 to survive exposure lasting for seven days to a 

 temperature of about - 200 C.), the inability of 

 starvation or desiccation to undermine their con- 

 stitution, combine to render the question of the 

 extinction of bacteria as remote as it is un- 

 desirable. 



Tempted by the prospects of exploring in this 

 newly-revealed world of life, investigators rushed 



