56p MICROBIOLOGY OF THE DISEASES OF MAN AND ANIMALS. 



Asiatic cholera, was introduced into the peritoneal cavity of the normal 

 guinea pig that the bacteria underwent lysis. He also noted that the 

 process was much more rapid in the immune guinea pig. Pf eiffer had the 

 idea in the beginning that lysis did not take place anywhere but in the 

 body of the animal, but later it was demonstrated by a number of men, 

 among them Metchnikoff, that the lytic action would also take place in 

 the test tube (in vitro). 



Bordet and others later showed that some normal sera possess the 

 power of liberating the hemoglobin in red blood corpuscles. These 

 hemolytic substances could be developed in the body of an animal if 

 that animal were injected or immunized with a suspenison of erythro- 

 cytes. The phenomenon of hemolysis is easily observed and studied 

 and the amount of the hemolytic agent can be accurately determined, 

 as the amount of hemoglobin liberated varies accordingly. The mecha- 

 nism of hemolysis and bacteriolysis correspond exactly and accordingly 

 much about the latter process was first worked out by experimentation 

 with hemolysins. 



Lytic substances can be prepared for a large number of bacteria and 

 for many body cells, as before stated. These bodies may be markedly 

 increased by the usual processes of immunization. Those substances 

 which have the power to produce lysins are called lysinogens and are 

 distinct antigens, as the lysins are antibodies. The lysins may be pre- 

 pared by injecting the live cells, the dead cells, the disintegration prod- 

 ucts of cells, and in some cases the metabolic products of cells. 



The Structures of Lysins. Lysins and bactericidal substances have 

 been shown to be composed of two distinct parts: one a thermolabile part, 

 known as the complement, which is destroyed at a temperature of 56 to 60 

 for thirty minutes, and another part which is thermostable, known, on 

 account of its double combining ability, as an amboceptor. This ambo- 

 ceptor will withstand heating to 60 for twenty-four hours, but if the tem- 

 perature is raised to 70 it is readily destroyed. If kept at ordinary room 

 temperature or in the ice box, amboceptor will remain active for years. 

 According to Ehrlich, amboceptors are the free chemical receptors of the 

 body cells. They are produced in the same way as antitoxins, but differ 

 from these bodies in that they have two combining groups, one known as 

 the cytophile group, with which the amboceptor combines with the bacteria 

 or other cells, and the other known as the complementophile group with which 

 it combines with the complement. The complement seems to be a normal 



