54 THE NATURE AND ORIGIN OF LIFE 



they will preserve it henceforward, until some other new 

 variation is produced. 



This wonderful fact of the conservation of acquired varia- 

 tions presents the greatest interest and will have to be studied 

 later. Quite apart from it, we must here and now verify 

 that, in living beings as simple as bacteria, partial destruc- 

 tion brings variation along with it. Such verification obliges 

 us to acknowledge that the bacterium is not formed of a 

 single and homogeneous substance, but of several elements 

 susceptible of separate destructive attack. Otherwise, there 

 would indeed be a diminution of the quality of bacter- 

 idia produced in the phenicated culture, but there would 

 be no variation. A body's change in qualities under the 

 influence of partial destruction of its substance proves that 

 the qualities of the body are not inherent in a single substance, 

 but in an aggregate of elements susceptible of separate de- 

 struction. An immediate consequence of this seems to be 

 that variation in the qualities of a living being must result 

 from variation in the respective qualities of its constituent 

 elements. Our second method of investigation will enable 

 us, in the fourth part of our book, to sift this idea more 

 completely. 



