The mitotic activity of bone marrow and thymus after combined antigenic challenge and trauma.

A significant increase in the mitotic rate of cells in thymus and bone marrow occurs 2--3 days after the infliction of various traumas or the injection of antigenic erythrocytes. This cell response probably occurs in order to produce the cells which are needed for the defence of the body after injury. The present investigation shows that the cell response after a fracture is abolished if the rats are fractured 3 days after injection of antigenic erythrocytes.