7o6 MICROBIOLOGY OF DISEASES OP MAN AND DOMESTIC ANIMALS 



dead cells, the disintegration products of cells and in some cases with the 

 metabolic products of, cells. 



The Structure 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 

 55° to 60° for thirty minutes; and another part which is thermo- 

 stable, known, on account of its double combining abihty, as an ambocep- 

 tor. This amboceptor will withstand heating to 60° for twentyrfour 

 hours but if the temperature is raised to 70° it is readjly destroyed. If 

 kept at ordinary room temperature or in the ice box amboceptors will 

 remain active for years. According to Ehrhch, 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 constituent 

 of the blood serum and other body fluids. It is undoubtedly produced 

 by the various body cells (leucocytes et. al) and during the immuniza- 

 tion of animals with certain antigens it is probably increased only 

 sUghtly, if any, in amount. The complement is supposed to be com- 

 posed of two groups also, one a'haptophore with which it combines 

 with the amboceptor, and another a zymophore which readily produces 

 the lytic action after the haptophore has combined with the ambocep- 

 tor. On heating the complement the zymophore group is destroyed 

 and a complementoid is produced. This substance is similar to a toxioci 

 and will combine with amboceptor but no lysis will result. It is, 

 however, the amboceptor, or .30-called immune body, that undergoes 

 the decided increase during the processes of immunization. It can. be 

 accurately demonstrated that the amboceptor must combine with the 

 cell in question before the complement can combine. Cells, such as 

 bacteria or erythrocytes, may be saturated with amboceptor and 

 washed and when the complement is added and combined, lysis takes 

 place. The complement will not combine with the cells under any 

 circumstances unless amboceptor is present and has first combined 

 with the cells. It is probable in a given serum or body fluid that there 

 are several complements which may activate a variety of amboceptors. 



