PRACTICE OF MEDICINE AND HYGIENE 



of human life is being lengthened; and pre- 

 ventive and curative medicine has become one 

 of the most beneficent forces within the grasp 

 of man for the promotion of human happiness. 



It was the study of animals by Darwin and Darwinism 

 his predecessors that gave the world the theory in medicine, 

 of evolution, which has been one of the greatest 

 instruments for its intellectual and moral up- 

 lift that history records. It put man in pos- 

 session of an understanding of his place in the 

 universe, and did more to free him from the 

 incubus of superstition and the dread of super- 

 natural powers than any other agency. It 

 lifted him from his grovelling attitude of sup- 

 plicating fear to the upright position, and 

 placed him squarely on his feet. 



Now the further pursuit of these same meth- 

 ods of study and experiment are showing the 

 relations of man and his parasites. Man, de- 

 scended from the cold-blooded amphibians, has 

 gradually developed a higher and higher body- 

 temperature. Every indication seems to show 

 that one reason for this was to make his blood 

 too warm to serve as a pabulum for the para- 

 sites which infested it. When the plasmodium 

 of malaria or some similar organism found its 

 way into the blood, the animal which perished 



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