ORIGIN OF DISEASE AND THE GERM THEORY. 157 



ever, these associated functions concur in animals, and in man, 

 not only when they are consciously and suitably directed to 

 the removal of a pain-giving agent, but also when the pain 

 cannot be thus removed, being due, as in disease, to causes of 

 quite a different nature. In the former case the reactions are 

 directed to measures of self-preservation, leading as they do, ta 

 redoubled efforts at defence, while in the latter case they may 

 be not only not beneficial but even of a very harmful and even 

 fatal character. 



When the pain results from morbid processes, the harm done 

 by the reactions of the organisms is oftentimes excessive, while 



Fig. 17. 



the benefit is reduced to a minimum, or may be entirely absent. 

 Thus, as in the case of ordinary physiological processes, so also 

 in those which are called abnormal, certain remnants of "antique 

 customs" still remain to clog the wheels of more highly 

 developed processes. Just as certain rudimentary structures,, 

 not only useless but even harmful, remain in higher animals to 

 interfere with the working of newly-constituted organs, so, too, 

 organisms may be said to make, now and again, great and 

 sometimes even fatal mistakes in the processes by which they 

 attempt to throw off the results of injuries, or to atone for 

 damaging changes. In other words, it seems that the working 

 of normal physiological mechanisms may be said to entail even. 



