CONCLUSION. 289 



the precise points which it is essential to explain. 

 But we must return to Robin's theory. When he 

 states that the microbe is only developed in tissues 

 which are already changed, Robin is not so far from 

 the parasitic theory as his pupils represent him to 

 be. It matters little that the microbe may be only 

 a complication, a secondary phenomenon, if this 

 secondary phenomenon dominates the whole disease 

 and invests it with its dangerous character, its con- 

 tagious and virulent nature. In the case of a viper's 

 bite, it is not the bite from the animal's teeth which 

 is dangerous, but the introduction of the venom 

 which flows from them; that is, the secondary 

 phenomenon. And it is the same with an anatomical 

 puncture. 



Two men in similar circumstances are attacked by 

 pneumonia; the first will recover with ease because 

 he is only thirty years old, while the other is almost 

 certain to die because he is seventy-five, but we should 

 not therefore say that he died of old age, and that the 

 pneumonia was only a secondary phenomenon. 



Oidium and the phylloxera have attacked the 

 French vineyards which are exhausted by excessive 

 cultivation, but it will not therefore be denied that 

 these are two dangerous diseases ; nor should we say 

 that they are secondaiy phenomena. It is therefore 

 evident that Robin's theory, as it is set forth by 

 his disciples, who have resuscitated statements made 

 twenty or thirty years ago, is no longer on a level 



