16 INTRODUCTION. 



have been lost sight of — to some extent even by him- 

 self — and the principle as it stands to-day in scientific 

 and philosophical discussion is practically synony- 

 mous with the Struggle for Food. As time goes on 

 this Struggle — at first a conflict with Nature and the 

 elements, sustained by hunger, and intensified by 

 competition — assumes many disguises, and is ulti- 

 mately known in the modern world under the names 

 of War and Industry. In these later phases the early 

 function of protoplasm is obscured, but on the last 

 analysis, War and Industry — pursuits in which half 

 the world is now engaged — are seen to be simply its 

 natural developments. 



The implications of the second function, Reproduc- 

 tion, lie further from the surface. To say that Repro- 

 duction is synonymous with the Struggle for the. Life 

 of Others conveys at first little meaning, for the 

 physiological aspects of the function persist in the 

 mind, and make even a glimpse of its true character 

 difficult. In two or three chapters in the text, the 

 implications of this function will be explained at 

 length, and the reader who is sufficiently interested in 

 the immediate problem, or who sees that there is here 

 something to be investigated, may do well to turn to 

 these at once. Suffice it for the moment to say that 

 the physiological aspects of the Struggle for the Life 

 of Others are so overshadowed even towards the close 

 of the Animal Kingdom by the psychical and ethical 

 that it is scarcely necessary to emphasize the former 

 at all. One's first and natural association with the 

 Struggle for the Life of Others is with something 

 done for posterity — in the plant the Struggle to pro- 

 duce seeds, in the animal to beget young. But this is 



