Between vomiting of blood from ulcer and from cancer of the stomach we have mostly these distinctions: in ulcer it follows soon after taking food, in cancer (this being generally at the pylorus), an hour or more after eating; ulcer is attended also by tenderness on pressure at a certain spot over the stomach, without tumor; cancer presents a tumor, with much less marked tenderness on pressure. By aid of the microscope in examination of the matter vomited this diagnosis may be completed. Constipation is an exceedingly frequent symptom under many and diverse circumstances. Pathologically, we account for it in several ways: 1, torpor of the muscular coat of the intestinal canal; 2, deficiency of secretion in the glands of the bowels and in the liver; 3, imperfect innervation of the abdominal organs; 4, mechanical obstruction, as by a foreign body, intussusception, strangulated hernia, cancerous or other tumor, stricture of the rectum, etc. Dyspeptic persons are ordinarily constipated. So are almost all patients at the beginning of attacks of measles, scarlet fever, small-pox, and other acute febrile maladies. Typhoid fever is scarcely an exception to this; although the bowels in that affection become loose after a few days, they seldom are so at the very beginning of the attack. Sea-sickness is commonly accompanied by total or nearly total inaction of the bowels, the secretion of the intestinal glands being almost null, often for many days together. Torpor of the brain is sometimes attended by marked constipation. The latter may be a contributing cause of the former, as in certain severe cases of scarlet fever, in which threatening coma may be relieved by active purgation. We must not, however, occupy space here by attempting to enumerate the many conditions under which constipation may present itself as a symptom. Almost as various are the associations of the opposite state of the bowels, diarrhoea. Excessive or abnormally frequent discharges from the bowels may be either fecal, bilious, mucous, membranous, purulent, bloody, fatty, or watery, and they may occur with or without pain and straining (tenesmus).