At first with sternum-puncture of the patients suffering from essential chloranemias (idiophathic hypochlomic anemia), the observations on the bone-marrow picture and the determinations of the O(2)-consumption and glycolysis had been conducted; and then, after adding the serum of the patient to the bone marrow of normal rabbit, in vitro, again the rates of the O(2)-consumption as well as of glycolysis of the bone marrow of the rabbits receiving continuously for one week injections of the same serum were determined. With these results and with comparative studies on the case of bleeding anemia with that of hook-worm anemia, the author have drawn the following conclusions: 1. The number of nucleated cells in the punctuate of the essential-chlorosis patient as well as the percentage of the erythroblasts in the bone-marrow picture increased; and the majority of the latter were basophilic; and furthermore, of those that were neutrophilic, promyelocytes and or metamyelocytes showed a slight increase in number while mature cells revealed a decrease. 2. The O(2)-consumption and glucolysis of the punctuate drawn from the patient showed an increase in the rate, the latter especially markedly; whereas the fat-free dry weight of the punctuate had been light but after the treatment it showed a tendency to return to normal. 3. On comapring the O(2) consumption and glycolysis of the bone marrow of the rabbits receiving continuous injections of the patient's serum with those of the bone marrow of the rabbits injected with the serum of the normal, no marked difference whatever could be recognized. 4. Similar comparative observations made with regard to the effects on the O(2)-consumption both in the case where the patient's serum had been added to the normal rabbit bone-marrow and where the normal person's serum to the rabbit's bone marrow, revealed no substantial difference. 5. A marked rise of the rates of both the O(2)-consumption and glycolysis of the punctuate from the patient is in a strange contrast to the case of hemorrhagic anemia where there is no change at all; and furthermore, the rise has a certain similarity to the rising picture of hookworm anemia but the degree of the rise in the case of this desease is far greater than that of the latter.