STUDY OF ACUTE SECONDARY ANEMIAS IN INFANCY

New facts concerning blood destruction and blood regeneration are constantly necessitating a revision of our conceptions of these conditions. Certain results are based upon generally accepted observations so that one is fairly safe in making definite deductions from them. Blood destruction is one of the routine tasks of the body and the replacement is the result of the continuous activity of a widely distributed hematopoietic system. Under normal conditions, the blood tissue is so constituted that it can withstand sudden and considerable changes, and the cells of the blood tissue are so flexible that throughout these changes their normal shape is retained. The rate of regeneration normally depends on the rate of destruction, which has been variously estimated at one tenth, one fifteenth or one thirtieth of the total blood each day. On the other hand, in cases of secondary anemia in which transfusions with a blood of a compatible