ENDOCRINE FUNCTION OF THE THYMUS GLAND 



331 



of the same, but inactivated serum, using rat serum as comple- 

 ment against rat corpuscles, was tested with an equally negative 

 result. 



We can see, therefore, that the hemolysin produced in the 

 rabbit by the injection of a suspension of rat corpuscles is very 

 small in amount, if any, in the first week after the first injection. 

 Unfortunately, the rabbit was killed by the second injection of 1 

 cc. of 10 per cent suspension, which seems to have been too large 

 a dose for a single injection. 



A large, well-developed male rabbit (rabbit, group C, no. 2) 

 was injected with rat corpuscles in smaller doses many times 

 repeated within several days and the blood tested for its hemolytic 

 activity against rat corpuscles. 



Immunization of a rabbit {rabbit, group C, no. 2) against the rat blood 



Date of injection Amount of erythrocytes injected intraperitoneally 



November 12, 1918 5 cc. of 5 per cent suspension 



November 19, 1918 5 cc. of 10 per cent suspension 



November 25, 1918^ 5 cc. of 10 per cent suspension 



December 1, 1918 Sample blood taken 



1 Before this injection some blood was taken for a sample hemolytic test. 



b. Hemolytic test of the serum in vitro 



1. Hemolytic test of the sample blood taken just before the third 

 injection. Active immune serum was tried for its hemolytic 

 power against rat corpuscles. The result is given in table 8. 



2. Hemolytic test with normal rat serum or normal guinea-pig 

 serum as complement. Hemolytic test of the inactivated antirat 

 blood rabbit serum, using normal rat serum as complement (1) 



