Pathological Changes following the Inoculation of Chick Embryos with Adult Cells II. BLOOD CELLS.

The pathological changes in the livers and spleens which occur after the inoculation of adult fowl blood into fifteen-day-old embryos have been followed for about 7 weeks. Three consecutive histological stages were noticed. The first two stages, termed the splenomegaly syndrome and the stage of lymphoid hyperplasia, closely resembled those described following the injection of adult spleen cells into fifteen-day-old embryos (Biggs and Payne, 1960). The third stage was found in chicks in the terminal stages of runt disease, and was characterized by involution of the lymphoid tissues. The significance of these changes is discussed. [ABSTRACT FROM AUTHOR]