Rabbits x-rayed in doses sufficient to reduce the amount of their lymphoid tissue without damage to the bone marrow showed a definite deficiency in the production of precipitins, bacterial agglutinins, and protective antibodies. On the other hand, rabbits subjected to exposures of dry heat sufficient to increase the activity of the lymphoid organs, on immunization develop antibodies in larger quantity than do untreated animals immunized by the same process.

This content is only available as a PDF.