EXTRACT XIV. 



ON THE f7S MEDIC ATR1X NATURAE" 



THIS phrase must be of considerable antiquity, and its 

 origin would be of some interest to know, inasmuch as it 

 points back to a time when the educated man had begun 

 to differentiate between the various agencies responsible 

 for the restoration to health of the diseased and maimed, 

 and to a period in the history of medical science when the 

 deeper aspects of biological processes and things generally 

 were beginning to present themselves for solution and 

 practical appraisement and application. It, moreover, 

 indicates a growing belief in the minds of thinking men 

 in the powers of nature, not only to cause disease, but to 

 effect its removal, to produce the bane, and to provide 

 the antidote. 



Nature, in evolving living forms from inert matter, 

 made each form perishable and ephemeral, embodying in 

 it the co-working of the principles of life and death, both 

 of which principles are absolutely essential in the great 

 evolutionary processes of advancement of type of organi- 

 sation, and the effacement of imperfect adaptation to 

 altering environment. 



In the process of organic evolution, the vis medicatrix 

 nature may be regarded from two different standpoints, 

 according to the two aspects from which we may study its 

 operations throughout the broad field of animated nature^ 

 the one aspect being the origin and perpetuation of living 

 forms, the other aspect being the limitation of individual 

 living forms to more or less exactly defined periods of 

 time and areas of space. 



