IMMUNITY. 333 



to carry conviction until recently, supported 

 by Gottstein and Schleich, I proved that a 

 specificity of this kind must depend chiefly 

 upon the fact that when a man acquires protec- 

 tive inoculation there must be stimulation or 

 excitation of those particular, specific organs, 

 tissues, cell-territories or cells which are es- 

 pecially involved in the disease in question. 

 Just as bacteria can be separated into species, 

 so also do differences exist between the cells 

 of the different species of host animals and also 

 between the cells of the various organs and 

 tissues of the individual organism ; the liver- 

 cell is not only a cell : it is more than that, it 

 is a liver-cell, and the liver-cell of a dog is not 

 only a liver-cell, it is the particular sort of 

 liver-cell pertaining to a dog. What is fair to 

 the bacterium is only fair to the body-cell. 



Still other reasons induce us to declare for 

 the preponderating significance of the body- 

 cells and against the determining influence of 

 the bacteria in bringing about the establish- 

 ment of specific tolerance of poisons. In the 

 first place it is very improbable that where a 

 genuine habituation to poison exists, or where 

 an establishment of tolerance of simple poisons 

 like ricin or abrin is effected, the habituation to 

 these poisons is bound up with the formation 

 of an altogether new and peculiar foreign body 



