BACTERIOLOGY IN A NUTSHELL. 



Hypothesis 

 of Ehrlich. 



Cellular 

 Activity. 



SUPPLEMENT. 

 The "Side Chain Theory" of Ehrlich. 



COMPARISON WITH "tHEORY OF METCHNIKOFf" 



* SERUM THERAPY. 



PART I. 

 Twenty-five years ago, in 1885, prior to the 

 discovery of toxins and antitoxins and before 

 scientific workers had discovered the real 

 nature of immunity, from far off Europe, Paul 

 Ehrlich, of the Royal Prussian Institute 

 for Experimental Research at Frankfurt, sent 

 forth to the world a small pamphlet, entitled 

 "The Oxygen^ Requirements of the Body." 

 In the course of argument therein, he gives 

 the opinion that food assimilation by the 

 body cells comes to pass only after the nutrient 

 substances and the essential part of protoplasm 

 have united chemically. He does not give us to 

 understand that assimilation is at an end when 

 this union takes place. He goes on to explain 

 his belief that certain molecules of complex 

 nature must divide, or split up, into very simple 

 substances or particles prior to their entrance 

 into the composition of protoplasm, In other 

 words, the constituent part of the cell which 

 unites with the food substance acts the part of 

 a link to bring the food particles into intimate 



* See initrodluction to FouTtih Edition Revised, pages 5-9. 

 162 



