STUDIES ON ANTIAMBOCEPTORS. 



653 



had to be derived from a rabbit. In the present instance it was an 

 inactivated serum obtained from a rabbit treated with ox blood. 

 Guinea-pig serum was used as complement. In order to exclude 

 the action of the antiamboceptor, a parallel experiment was made 

 in which the amboceptor consisted of the inactivated serum of a 

 goat immunized with ox blood, guinea-pig serum being used as 

 complement. For the sake of simplicity we shall term the ambo- 

 ceptors respectively " rabbit amboceptor " and "goat amboceptor." 

 The experiment is as follows: 



Two series of test-tubes were prepared, decreasing amounts of the anti- 

 serum being placed in each tube. The volume in each tube was always made 

 up to 1.0 cc. with physiological salt solution. To the tubes in series A was 

 then added 0.0015 cc. (H solvent doses) of the rabbit amboceptor; while the 

 tubes of series B received 0.015 cc. goat amboceptor (1 solvent doses) plus 

 0.0015 cc. normal inactive rabbit serum. Both series of tubes were kept 

 at room temperature for three-quarters of an hour, after which 1 cc. of a 5% 

 suspension of ox blood-cells was added to each tube. After incubation at 37 

 for one hour, the tubes were centrifuged, the sediments resuspended in physiog- 

 ical salt solution, and mixed with guinea-pig serum as complement. The 

 amount of complement also equaled H solvent doses, being 0.075 cc. in seres A, 

 and 0.05 cc. in series B. After this the tubes were kept at 37 for two hours, 

 and then placed in the refrigerator over night. The result noted the next 

 morning is shown in tho following table: 



TABLE I. 



amboceptors for ox blood. So far as the production of antiamboceptors or of 

 antibodies against the albuminous substances is concerned, this is immaterial. 

 Controls made with the serum of a goat immunized with normal rabbit serum, 

 yielded the same results. The quantity of the latter available was too small 

 to suffice for all of the experiments here reported. 



