Abstract
1. Egg white or ovalbumin (E. MERCK) were repeatedly injected into the ear vein of adult rabbits, and the mode of reaction of the liver, spleen, and bone marrow to these agents was observed.
2. Following repeated injection of these agents there appeared in the peripheral blood a marked lymphocytosis with a significant rise in the average number of mitochondria in lymphocytes, and the lymphatic tissue of the chief lymphoid organs underwent a marked hyperplasia. These changes reached their maximal intensity about 7 days after the initial injection, and at about 14 days a striking accumulation of lymphocytes occurred in the periportal spaces of the liver. None of these processes of lymphatic reaction, however, was accompanied by any noticeable rise in antibody titer.
3. The lymphatic reaction gradually declined thereafter, and was substituted by an extensive plasmocytic reaction which began to appear about 14 days after the initial injection. The plasmocytic reaction occurred most intensely in the splenic cords, next in the bone marrow, and relatively feebly in the liver. It was accompanied by a marked rise in antibody titer.
4. In the spleen and bone marrow lymphatic and plasmocytic reactions occurred independently in different portions, but in the liver the lymphocyte aggregations formed in the periportal spaces were substituted gradually by plasmocytes, giving the impression as if the lymphocytes had transnsformed into plasmocytes. However, no direct evidence was obtained to indicate such cellular metamorphosis.
5. The fact, that the animal responds to the stimulation of heterogeneous protein first by lymphatic reaction which is substituted successively by plasmocytic reaction, is of interest as indicating that the lymphatic reaction represents an initial step of the defense mechanism of the organism against exogenous noxae.
