6 Veterinary Medicine. 



the blood of the injected animal, the formation of hsemolysins 

 which act on the red globules of the blood of the rabbit but not 

 on that of other animals. This operates when the blood serum 

 from the injected horse or guineapig is injected into the circulat- 

 ing blood of the rabbit, or mixed with the rabbit blood in vitro, 

 (Bordet). Here we have a suggestion of immunization. The 

 alien and inimical blood of the rabbit in the circulating blood of 

 the horse (or other animal) educes the protective hsemolysin which 

 quickly destroys the alien red blood globules of the rabbit if 

 brought in contact with them. The hsemolysin, however, is com- 

 posed of two bodies one of which (^alexin, complement') is rendered 

 inactive when heated for half an hour to 55° C, and a second 

 {immune body, sensitizing body, ambocepter, copula, fixative sub- 

 stance, desmon, preparatory only loses its power at a heat of 60° 

 to 65° C. The serum robbed of its hsemolytic power by heating 

 to 55", resumes this power if mixed with the blood serum of a 

 healthy guineapig, which would not of itself have affected the 

 rabbits' blood. The alexin shows no affinity for the red globule, 

 to which it proves harmless except in presence of the ambocepter. 

 Again, alexin and amboceptor show no affinity at a low temperature 

 but may lie side by side at o°C. without uniting, and can only do 

 so at a higher temperature up to 40°C. The alexin shows no 

 affinity for the cell unless the amboceptor is present, but, given the 

 two conditions, affinity between the alexin and ambocepter and a 

 corresponding affinity between the ambocepter and the cell, and 

 the microbian toxin can reach the cell and exercise its baneful 

 influence upon it. 



Ehrlich carries the subdivision still farther. The amboceptor 

 has its haptophore group, (aptein, to touch, pherein, to bring), 

 intermediate between it and the animal cell as an essential 

 element to the completion of the mutual affinity of the two, and 

 the alexin or complement has its toxophore group, {toxos, poison, 

 pherein, to bring), which on that side carries the toxins. Thert 

 on the part of the cell he invokes projections of the cell wall in 

 the form of pseudopodia {receptors') which must have a special 

 affinity for the haptophores in order to establish an effective union 

 with the amboceptor and complement, and finally with the toxin 

 and microbe. 



The relation of one of these bodies to its fellow is of the nature 



