160 ORIGIN OF NATURAL IMMUNITY. 



In this pcaper I have endeavoured to show : — 



(1) That tliere is a close analogy or identity between the pro- 

 duction of bacteriolytic bodies and the digestion of food. 



(2) That bacteria do traverse the intestinal wall, and that 

 negative experimental results regarding the same are untrust- 

 worthy. 



(3) That natural immunity, especially towards the l)acteria that 

 normally inhabit the intestinal tract, is occasioned and maintained 

 by the comparatively few bacteria which, in crossing the intesti- 

 nal wall and possibly gaining access to the body fluids and organs, 

 stimulate the cells to produce immune bodies. 



(4) That the asrglutination of bacteria may play a much more 

 active part in the production of immunity than is generally 

 supposed. 



