THE CAUSATION OF DISEASE. 89 



ground about the place. The multitude then wildly pressed 

 in upon the fatal spot, and the foremost among them dipped 

 their hands or handkerchiefs in the- blood. One of these 

 rushed with bloody fingers after a group of gay women, striving 

 to add to the rouge on their faces, and the women ran shriek- 

 ing away." 



Here we see the humanity of man for the time completely 

 stifled, and the dormant instincts of his savage ancestors 

 awakened. The history of the civilized world shows how ever 

 ready these savage instincts are to crop up on the removal of 

 the inhibitory influence of a loosely-attached humanity. The 

 events of Pranzini's execution call to mind many very similar 

 instances furnished by the history of the persecutions of the 

 Christian Church. 



Again, in the gradual dissolution of old age, how often do 

 we observe the mental faculties falling away in the inverse 

 order of their ancestral evolution ; * and it not unfrequently 

 happens that the moral faculty dwindles, while the intellectual 

 powers remain in full vigour. 



That structural characters of latest ancestral origin are most 

 apt to disappear under disturbing influences is nowhere better 

 shown than in the processes of disease. This conclusion might, 

 I think, be arrived at a priori. 



Whether or not all diseases are accompanied by structural 

 alteration is a question that will be discussed in another part ; 

 but this much is at once certain, that where distinct structural 

 change does occur, the process is one of dissolution. In a few 

 instances, such as the more highly organized tumours, this 

 may not seem to be the case ; but it is at once evident that, in 

 the vast majority of diseases accompanied by structural change, 

 there is distinct tissue dissolution. There is no advance, no 

 improvement, in the affected tissue ; on the contrary, there is 

 retrogression, deterioration — and this is dissolution. 



Evolution and dissolution are opposite processes : the one 

 may be roughly defined as a building-up, the other as a pulling- 

 to-pieces. Now, the fact that disease is a vital process suggests 



* I use the term " ancestral evolution " in contradistinction to those evolu- 

 tionary processes which take place in the individual, not as the direct result 

 of heredity, but of personal acquisition. 



