64 WARFARE IN THE HUMAN BODY 



in evolution is of much greater importance than that of 

 mere elimination. But pathology has very naturally 

 been neglected as a study by biologists. On the views 

 generally held, it has seemed sufficient to recognize that 

 disease destroyed organisms which obviously left offspring, 

 if it left them at all, that were handicapped even more 

 heavily than their parents. It has been understood that 

 their elimination was only a matter of time, and that neither 

 their virtues nor their failures could influence the race. 



If there is one thing more than another which has 

 struck me when attempting to study these questions, it 

 is that too many men of science appear to believe that 

 any serious investigation of other branches than their 

 own is for them a waste of time. In no case is this more 

 common than in that of the biologist, who yet, by the 

 very name and nature of his task, should include in his 

 apparatus a considerable knowledge of everything which 

 deals with the organic, and even inorganic, world. Science, 

 however, is kept in more or less water-tight compartments, 

 and it seems left to the mathematician to hold the opinion 

 that his own branch of learning has, somehow or another, 

 deep relations with all things, including life itself. Even 

 by him it does not seem to have been pointed out that 

 in things living and non-living certain principles of con- 

 struction rule alike. However much they were wedded 

 to mechanico-physical explanations, biologists have 

 assuredly often ignored the fact that any organism is 

 construction, and knowing little of the laws of construc- 

 tion have ignored basal facts familiar to every architect 

 or even every artisan. It was reserved for Wolff, in 

 formulating his law of bone-growth and reaction to stress, 

 to propound a principle more far-reaching than he recog- 

 nized, when he showed that living bone, reacting to normal 



