64 EVOLUTION, SOCIAL AND ORGANIC 



Struggle was foreshadowed in a paper read by 

 Weismann at the meeting of the Association 

 of the German Naturalists at Salzburg, two 

 years earlier, in 1881. 



This paper was entitled "The Duration of 

 Life," and the subject was still further devel- 

 oped in an academic lecture, in 1883, o^ "Life 

 and Death." These two biological contribu- 

 tions not only indicated the foundations of 

 Weismann's theory, but they threw a very 

 brilliant light in certain very dark places. 

 Weismann not only took up, but he solved 

 the hitherto obscure question of the origin of 

 death. 



Johannes Muller had, as early as 1840, re- 

 jected the prevailing hypothesis which held 

 the death of animals to be due to "the influ- 

 ences of the organic environment, which grad- 

 ually wear away the life of the individual." 

 Muller argued that if this were so "the or- 

 ganic energy of an individual would steadily 

 decrease from the beginning." Everybody 

 knows, however, that in spite of the wear and 

 tear caused by the "environment," be it or- 

 ganic or inorganic, the volume of life in- 

 creases, until a certain stage is reached in 

 all animals. But Muller had failed to fill the 

 gap his criticism had created. 



