6 THE MECHANISM OF LIFE 



one of another, and thus form an uninterrupted chain from 

 the infinite of the past into the infinite of the future. A 

 living being gathers from its entourage a supply of matter and 

 of energy, which it transforms and returns. It is part and 

 parcel of the medium in which it lives, which acts upon it, 

 and upon which it acts. The living being and the medium 

 in which it exists are mutually interdependent. This medium 

 is in its turn dependent on its entourage, — and so on from 

 medium to medium throughout the regions of infinite 

 space. 



One of the great laws of the universe is the law of 

 continuity in time and space. We must not lose sight of this 

 law when we attempt to follow the metamorphoses of matter, 

 of energy and of form in living beings. Evolution is but the 

 expression of this law of continuity, this succession of 

 phenomena following one another like the links of a chain, 

 without discontinuity through the vast extent of time and 

 space. 



The other great universal law, that of conservation, applies 

 with equal force to living and to inanimate things. This law- 

 asserts the unereateability and the indestructibility of matter 

 •and of energy. A given quantity of matter and of energy 

 remains absolutely invariable through all the transformations 

 through which it may pass. 



^Ye need not here discuss the question of the possible trans- 

 formation of matter into ether, or of ether into ponderable 

 matter. Such a transformation, if it exists, would have but 

 little bearing on the phenomena of life. Moreover, it also 

 will probably be found to conform to the law of conservation 

 of energy. 



In marked contrast to the permanence of matter and of 

 energy is the ephemeral nature of form, as exhibited by living 

 beings. Function, since it is but the resultant of form, is 

 also ephemeral. All the faculties of life are bound up with 

 its form, — a living being is born, exists, and dies with its 

 form. 



The phenomena of life may in certain cases slow down 

 from their normal rapidity and intensity, as in hibernating 



