86 EXPERIMENTAL RESEARCHES 



death on the sixteenth day ; 0-25 c.c. of the 

 mixture, death on the tenth day. 



Naturally one can only expect to find such 

 marked differences in the case of those sub- 

 stances which owe their origin to a certain 

 organ or combination of organs. If the place 

 of origin of other haptines is widely diffused 

 throughout the connective tissue of the organ- 

 ism, one can scarcely hope in such a case to 

 achieve much of value for diagnostic purposes. 

 An extensive organisation, which does not con- 

 fine itself to investigation of a single haptine- 

 substance, or indeed to a few such, is therefore 

 necessary, in order that more exact analyses 

 may be made, and results of a practical value 

 be obtained. 



Looking back upon what I have said, you will 

 see that it is the principle of distribution which 

 governs the processes resulting in active im- 

 munisation. The antibodies the protective 

 substances in the serum all possess the power 

 of reacting, with maximum chemical energy, 

 with their corresponding antigen, as, e.g., in the 

 anchoring of bacterial cells. This anchoring is 

 a necessary preliminary for further reaction, 

 which may be of the most varied kind. 

 We are acquainted with a number of such 



