io6 EVOLUTION OF THE EARTH 



state of colloidal suspension, for it is in this state that the 

 life elements best display their incessant action, reaction and 

 interaction. 



With this assemblage, mutual attraction, and colloidal con- 

 dition, a fourth hypothesis is that there arose the rudiments of 

 competition and selection. "Was there any stage in this group- 

 ing, assemblage, and organization of life forms, however 

 remote or rudimentary, when the law of natural selection did 

 not operate between different unit aggregations of matter? 

 Probably not, because each of the chemical life elements pos- 

 sesses its peculiar properties which in living compounds best 

 serve certain functions. This cooperation was also an appli- 

 cation of energy new to the cosmos." In other words, every 

 "life element" has its single and multiple services to render to 

 the organism. 



And as a fifth hypothesis relating to the origin of organisms, 

 Osborn advances the idea that the evolution and specialization 

 of various enzymes has proceeded step by step with the evolu- 

 tion of plant and animal functions, "since in the evolution from 

 the single-celled to the many-celled forms of life and the multi- 

 plication of these cells into hundreds of millions, into billions, 

 and into trillions, as in the larger plants and animals, bio- 

 chemical coordination and correlation become increasingly 

 essential." 20 



Conclusion. Such are the principal attempts of modern 

 biologists to formulate in some concrete way the evolution of 

 matter in the living state from the elements of the earth. 

 Their consideration is valuable in that it indicates the uni- 

 formitarian trend which, at the present day, biological thought 

 follows in this field, and also the diversity of results arrived 

 at by the scientific imagination when it is largely untrammeled 



20 Osborn, H. F., "The Origin and Evolution of Life upon the Earth." Scien- 

 tific Monthly, vol. 3, 1916, pp. 5-22, 170-190, 289-307, 313-334, 502-513, 601-614. 



