The problem of maintaining, over long periods, normal erythrocyte levels in patients with pernicious anemia is one which presents itself to every physician who has such a patient to treat. In the larger hospitals and medical centers many data concerning this problem have been assembled, and from time to time some of these have been published. Since the purpose of this paper is to present the results of maintenance treatment of the patient with pernicious anemia by parenteral injection of liver extracts over relatively long periods, perhaps a fairly comprehensive review of the literature pertaining to the results obtained by this means will be of value. It was pointed out in the early reports1of the use of intramuscular injections of liver extract that observation over long periods is necessary in order to establish the average maintenance dose. Six months may be considered the shortest period over which patients