ANTISEPTIC SURGERY 155 



plants created a certain presumption in favor of 

 the germ theory of disease, which is simply an ex- 

 tension of the notion of parasitism to more minute 

 forms of life. From the grosser parasites such as 

 lice and bed bugs, which are spread from person 

 to person, the smaller itch mites and worms respon- 

 sible for itch, trichinosis, and hook-worm disease, 

 down to the minute one-celled animals and plants 

 we have a graded series of attacking forms bent 

 upon the common aim of getting their living at the 

 expense of another organism. 



Disease from the standpoint of the germ theory 

 is simply a result of the very common and wide- 

 spread biological phenomenon of predatory activity. 

 From this standpoint the mystery of contagion 

 vanishes. The period of incubation common to all 

 contagious diseases receives an almost obvious ex- 

 planation as due to the time required for the enter- 

 ing pathogenic organisms to multiply until they are 

 numerous enough to provoke disturbing symptoms. 

 And the course of a disease is a consequence of the 

 varying outcome of the struggle between the body 

 and its invading enemies. 



In 1873 Pasteur became a candidate for mem- 

 bership in the Academy of Medicine and was 

 elected by a majority of one vote. He valued his 



