An operative technique was evolved permitting successful partial hypophysectomy in guinea pigs.
Such animals, when immunized to Bacillus typhosus, produced specific agglutinins in the same quantity and at the same rate as unoperated and operation controls immunized at the same time and by the same method.
In guinea pigs previously immunized to Bacillus typhosus and hen red blood corpuscles partial hypophysectomy had no effect on the continued production and persistence of typhoid agglutinins, hemagglutinins, and hemolysins.
In guinea pigs immunized to Bacillus typhosus both the continued ingestion and the intraperitoneal injection of the whole pituitary gland extract (Burroughs Wellcome) had no effect on the subsepuent agglutinin titers as compared to that of normal animals.
The experiments would appear to show either that the hypophysis does not play an important direct or indirect part in the production of and persistence in the blood of typhoid agglutinins, hemagglutinins, and hemolysins, or that the amount of hypophysis left behind in the operation in order to maintain life is adequate also to exercise the degree of functional influence on these processes which the entire hypophysis conceivably exercises.