Aranea is especially noted for its production of symptoms analogous to those resulting from, malarial poisoning, and has been chiefly used in such cases when the cold stage is the most pronounced, and when the symptoms return precisely at the same hour. Aranea was selected by Dr. Von Grauvögl as typical of what he called a " hydrogenoid " constitution, where there is too much water in the system ; the patient being always deficient in warmth, and very susceptible to moisture or dampness, such a condition being especially favorable to malarial poisoning. Characteristic symptoms.