228 THE CAUSATION OF DISEASE. 



for the continued soaking of the tissues with alcohol does not 

 the better enable them to withstand its evil effects. In such 

 a case, therefore, the adaptation would be by indirect equili- 

 bration, and it would further be a mental adaptation : there 

 would be a survival, namely, of those capable of resisting the 

 temptation. It is impossible for any class to become corpo- 

 really adapted to an unlimited indulgence in alcohol. 



Again, let us take the case of the brain worker, leading 

 a life of muscular inactivity. 



Out of many individuals devoting their lives to mental 

 work, several will undoubtedly succumb to the E which it 

 entails. If an individual, for instance, have a strong muscular 

 development, and if, as not unfrequently happens, his brain 

 work entails a life of muscular inactivity, such inactivity 

 may lead to serious health disturbance — it may, indeed, 

 indirectly cause death. Such a person should on no account 

 be suffered to remain inactive, for his muscular development 

 is a clear indication that he comes of a stock which for 

 numerous generations has been accustomed to a vast amount 

 of bodily activity, and his entire corporeal and mental being 

 has become organized with a view to such activity. An 

 active E is normal to such an individual, an inactive one, 

 abnormal. Doubtless, a considerable degree of personal adap- 

 tation may occur, but it can never take place to the fullest 

 extent in the case of a very actively constituted individual. 

 People thus circumstanced will tell us how strongly their 

 instincts urge them to exercise, and that they never feel well 

 when they are unable to indulge in it daily. 



Many individuals, however, and such may be quite healthy, 

 are of more slender muscular build. These probably come of 

 a stock unaccustomed for many generations to great muscular 

 activity. I do not, of course, allude to such as are muscularly 

 weak through a general depravity of health and physique. A 

 typical "cockney," for instance, may be descended from very 

 muscular, country-born grandparents, and yet possess a very 

 feeble muscular system, but this muscular inadequacy will be 

 due to a universal physical depravity, consequent upon the un- 

 favourable conditions under which he has grown up. Of such 

 I am not now speaking, but rather of those who, while they 



