_a._ Normal Red Corpuscle (normocyte). _b, c._ Anæmic Red Corpuscles. _d-g._ Poikilocytes. _h._ Microcyte. _i._ Megalocyte. _j-n._ Nucleated Red Corpuscles. _j, k._ Normoblasts. _l._ Microblast. _m, n._ Megaloblasts. Gibson has suggested the formation of a chart where the number 10,000 of leukocytes shall appear upon the same line with 75 per cent. as the average normal proportion of polynuclears. Then drawing a parallel line, which shall indicate on one side each 1000 in increase of the former and each advance of one in the percentage, it will be seen that 15,000 leukocytes will correspond to 80 per cent. of polynuclears, 20,000 to 85 per cent., etc. When upon this chart there is drawn a line between that dot which represents the total leukocytosis on one side and that on the other which indicates the percentage of polynuclears, then the more horizontal this line the less the disproportion, while the more marked the angle it makes with the base line the greater the disproportion appears. It furnishes an admirable graphic record which the eye appreciates at once. It would appear, then, that a differential blood count made in this way, and thus recorded, affords the most valuable diagnostic and prognostic aid in acute surgical diseases, indicating especially the presence of suppuration or of gangrene. =Glycogen in the Blood and the Iodine Reaction.=--Glycogen occurs in the blood especially in three classes of cases: those where there is marked respiratory disturbance in certain of the anemias, and, what is of especial interest to the surgeon, toxemias, either of chemical or bacterial origin. It is usually present in the secondary and pernicious anemias as well as in acute and late leukemias. It is considered by some that in these cases it really indicates the occurrence of some bacterial infection. Especially is glycogen present in cases of suppuration and surgical sepsis, _i. e._, in those cases where leukocytosis is usually, but not invariably, present; indeed, it would seem to be a most significant indication. While the iodine test is more easily carried out than is a blood count, the latter affords more information. The reaction is reliable and its relative intensity gives an idea of the intensity of the inflammatory process. In many cases with obscure symptoms and without leukocytosis its presence will afford much aid in diagnosis. It is of great assistance also in distinguishing between a deep-seated pneumonia and serous pleurisy, since in the latter there is no reaction, or in distinguishing between pleurisy with effusion and empyema; again, in distinguishing gonorrheal arthritis from true rheumatism. In a case of strangulated hernia the presence of the iodine reaction would indicate that pressure had produced gangrene, whereas its absence would indicate a relatively lesser degree of destruction. It has been aptly said that the presence of iodine reaction indicates that the patient is seriously sick.