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 secondary 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 
