COLLECTED STUDIES IN IMMUNITY. 



the ox blood-cells, the second, 7-, only in goat blood-cells, and the 

 third, /?, in both. If a rabbit is injected with ox blood, the ambo- 

 ceptors (immune bodies) corresponding to groups a and /? will be 

 formed. Ox blood-cells, by means of their a. and /? groups, will 

 then be able to anchor all the immune bodies, whereas goat blood- 

 cells will anchor only the immune body of portion /?, leaving the 

 immune body of portion a. in the solution. 



If, as this explanation assumes, the goat blood-cells possess a 

 certain portion ofr eceptors which are common to goat and ox blood- 

 cells, it is essential that by treating rabbits with goat blood an immune 

 body should be obtained which likewise would act on both species 

 of blood. This, in fact, is the case. And here, as in the first case, 

 the solvent power for the two species of blood-cells usually differs, 

 though of course the relations are reversed from those in that case, 

 .as can be seen by reference to Table II. 



TABLE II. 



ACTION OF THE IMMUNE BODY OF THE RABBIT WHICH HAD BEEN TREATED WITH 

 GOAT BLOOD, ON GOAT BLOOD, AND Ox BLOOD. 



(Reactivation with guinea-pig serum. ) 



1 On employing the same serum on a different ox blood, 0.05 cc. produced 

 no solution at all, and 0.1 cc. merely a trace. This is evidently due to a casual, 

 individual lack of receptors in the ox blood-cells in question, such as showed 

 itself so frequently in goat blood when we studied isolysins. 



Because of these ratios we shall have to assume that the goat 

 blood-cells in this case possess a second system of binding groups 

 which is peculiar to them and represented in the above diagram 

 by f. They possess these, of course, in addition to the receptors, p 

 which they have in common with the ox blood-cells. In accordance 

 with this, in the elective absorption test in this case, the goat blood- 

 cells will bind the entire lot of immune bodies; whereas when ox 



