ANAPHYLAXIS 249 



sensitiveness is due to a lysin which sets free from the 

 bacteria a true endotoxin. 



Infection and intoxication arouse in the body a many- 

 sided conflict between these coagulins and lysins, which are in 

 general the good and evil antibodies. A lytic action may, 

 however, be salutary when it occurs slowly, whereas it is lethal 

 when it takes place abruptly : under these formulse may be 

 arranged all the facts mentioned in the course of this chapter. 

 " Although diametrically opposed to each other, as inevitable 

 results from their definition, immunity and supersensitiveness 

 may co-exist in the same individual, as well as succeed each 

 other, often again and again." 



Nicolle's theory is frankly inclined to the physical theory of 

 immunity, without overlooking the intimate relations which 

 exist between the physical properties of bodies, and their 

 chemical constitution. It also sees in immunity phenomena of 

 nutrition; for the body digests the antigens, and the theory 

 supposes simply that every digestive act is due to the successive 

 application of a coagulin and a lysin. 



