WHAT IS PHYSICAL LIFE 



Meantime, this great division of the liv- 

 ing kingdom still exists as great as ever, 

 and proportionately great in its influence 

 upon the life of all present and more re- 

 cent living things, ourselves included. In 

 our next chapter we shall see that we live 

 here only on temporary sufferance by the 

 unicellular things, which sooner or later 

 will put an end to our earthly existence. 

 This subject, therefore, becomes a very 

 practical one for us, multicellular beings, 

 as all our Health Officials will testify. 



On the other hand, we cannot but con- 

 sider it strange that this greatest of the 

 divisions of the living kingdom is wholly 

 ignored by writers on biology. Darwin 

 himself never once referred to it, though 

 as his great work had for its title the 

 Origin of Species, he would have found 

 better examples of settled and definite 

 species among the bacteria alone than he 

 would have found anywheie else. This 

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