78 EVOLUTION 



clearly discerned that there are only two: 

 the living and the non-living, the truly organ- 

 ized and the merely aggregated. Hence in 

 his immortal "System of Nature" he unites 

 Animalia and Vegetabilia as Organisata, and 

 separates Mineralia as Conserta. True, he 

 falls somewhat from this again, witness his 

 famous, but very fallacious, aphorism 

 "Minerals grow; Plants grow and live; 

 Animals grow, live and feel"; yet the great 

 distinction of life is not lost sight of. 



Since Claude Bernard, more than a genera- 

 tion ago, wrote his famous book, "Pheno- 

 menes de la vie communs aux animaux et 

 aux vegetaux," it has been recognized that 

 the beech-tree feeds and grows, digests and 

 breathes, as really as does the squirrel on its 

 branches; that in regard to none of the main 

 functions (except excretion, which plants 

 have little of) is there any essential differ- 

 ence; and that plants, though for the most 

 part, as it were, asleep, give many striking 

 illustrations of their power of movement and 

 their irritability. 



We must remember also that plants and 

 animals are alike in fundamental architec- 

 ture, being built up of cells and various mod- 

 ifications of cells. And there is a third deep 

 resemblance, that when we trace a beech- 

 tree or a squirrel back to its individual begin- 



