The fall in blood chloride caused by histamine (as a result of the gastric stimulation which this substance induces) is frequently accompanied by a rise in blood sugar. Similar inverse changes may follow sham-feeding or partial obstruction of the intestine. However, after denervation of the adrenals or double adrenalectomy, injection of histamine does not elicit this inverse change, although the fall in chloride may still occur. Fluctuation in the blood sugar, produced by pancreatectomy or by insulin administration, are accompanied somewhat more constantly by the inverse change in the chloride. Ni believes that, while the variations in blood sugar are not dependent on the chloride, those in blood chloride produced by insulin, etc., are directly related to the sugar fluctuations, and may be due to an effort at osmotic and other compensations. Dogs were the experimental animals.