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fluence of cold, of a condition to winch he was not accustomed and perhaps 

 wholly unadapted. If. on the other hand, we take an inhabitant of the 

 frigid zone and put him in a warm country, we would in all probability 

 find another series of complaints. In the temperate zone where there is 

 an alteration of heat and cold, one might say six months of tropical life 

 and six months of arctic life, many individuals cannot adapt themselves 

 to this semi-annual change, and as a consequence they suffer. 



Again, the individual who has been brought up on plain, substantial 

 food in the country, free from all infectious matter, may complain greatly 

 if confined to the food obtained in the city, which has passed through 

 many hands. The milk which so well agreed with him in the country may 

 be a veritable poison to him in the city; even the drinking-water may 

 disagree. 



We see this again illustrated in the matter of air conditions. The 

 man who has always lived under good air conditions, and whose ancestors 

 have lived under such conditions, may complain greatly on removal to a 

 dirty city where the air is loaded with dust derived from different sources, 

 partly from the bodies of those who are diseased. Such an individual may 

 have a sound body and may have sound health under his proper environ- 

 ment, but he may complain in the city simply because his body reacts to 

 the abnormal environment. Thus, if he inhales much dust, there may be 

 cough — nature's way of getting rid of offending material. The dust may 

 set xip a profuse flow of mucus, resulting in so-called catarrh — and yet 

 this may be simply a natural reaction of the body in protecting the res- 

 piratory organs and in getting rid of the inhaled dust particles, which are 

 brought up with the mucus in the process of coughing and hawking. Vari- 

 ous pains may come on, yet they are to be looked upon as warnings from 

 nature — to change the environment. When an individual does change and 

 finds all these symptoms of illhealth (not of real disease) disappear, 

 that ought to clearly indicate to him the conditions under which he should 

 live. If he persists in living under the abnormal environment, we know 

 what will happen : nature is constantly weeding out the unadapted — a 

 process that has been going on for countless ages, and still continues. The 

 doctrine of the Survival of the Fittest is a terrible reality from the stand- 

 point of the biologist and physician. 



One may come into a new environment and discover that there is 

 a non-adaptation. The thoughtful man will see two courses open ; first, 



