The highest red cell count made was 5,400,000, in a case of cancer of the uterus, in a patient aged 52, the count being 4,064,000 on entering the hospital. The highest hemoglobin index was 90 in a number of severe cases, and 100 in one case of sarcoma, to be detailed in the next lecture. In one recurrent case of cancer of the left breast, which was very distressing at first, the patient died peaceably and without pain, with a hemoglobin index of 90, and 4,900,000 red cells, and 7,400 white cells, of which 75 per cent were polynuclears, 17 per cent small lymphocytes, and 7 per cent mononuclears. Her hemoglobin had been 70 per cent on entering the hospital with 3,360,000 red cells. The highest leukocyte count observed was 18,600 in a case of inoperable cancer of the right breast, not long before death, in an unmarried female of 53; but in the course of treatment it had fallen to 6,200, about normal, from 10,520 before beginning treatment. I will not weary you with more of these figures, which are interesting and instructive as one studies them week by week in connection with the physical condition of the patient. However much can be done for these distressing and inoperable cases of cancer, one has to acknowledge that when general carcinosis has set in we are still helpless in arresting the lethal progress of the disease, although very much can be done in prolonging life and alleviating suffering; and this does not mean with morphia or codeia which in the end does harm, and was very seldom administered to the patients referred to. Forbes Ross, after ten years of constant microscopic clinical and surgical research, has made some interesting observations, covering many pages, on the blood of cancer patients, which have a close bearing on our subject, and to which I can only briefly allude, and I do not know if I can make it clear in the time I can give to the subject. By long study of sections of carcinomatous tissue he claims that the mononuclear leukocyte behaves in a very different manner from the polynuclear. Briefly he charges the mononuclear white corpuscles with actually producing the disease, by conjugating with certain epithelial cells, thereby giving them the reproductive capacity which enables them to push forward on their destructive career. The polynuclears seem to come up to the defense of the body, but are overcome by the poison secreted by the rapidly growing tumor cells.