98 THE NATURE AND ORIGIN OF LIFE 







ties transportable in dead colloids ; and this is enough to 

 prove that vital phenomena are not essentially different from 

 other natural phenomena. Only we must take as living 

 only that body which has all the attributes of a living 

 being. 



Diastases and Excrementitial Substances : Physical 

 Assimilation or Digestion 



The foregoing example alcohol fabricated in a sugared 

 must by means of a dead colloid coming from a yeast 

 brings up at once a question that seriously complicates the 

 method of analysis by decomposing the total vital activity 

 into partial activities transportable in colloids. 



At one and the same time two processes are going on 

 assimilation by a living substance, either in the strict sense 

 in a constant medium, or functional assimilation or adapt- 

 ation under new conditions of the medium ; and the produc- 

 tion of accessory substances of the assimilation. The latter 

 are oftenest called excrementitial ; they are indicated by 

 the letter R in the equation of elementary life as manifested 

 (p. 49). They are chemically defined substances and are 

 produced always the same just so long as the conditions of 

 life in the species studied remain the same. Such, for ex- 

 ample, is alcohol, an accessory to the assimilation of sguared 

 must by beer yeast. 



There is not the slightest comparison possible between this 

 excrementitial substance alcohol and the dead colloid which, 

 extracted from a culture of beer yeast, is able to produce the 

 alcohol in a sugared must. 



Speaking generally, diastases or enzymes are the dead 

 colloids able to transport with themselves a part of the vital 

 activity of a living being. The diastases we know only by 

 their effects ; and these are precisely the expression of the 



