J_ HIS paper reports an investigation that is primarily a systematic study of hydrochloric acid secretion during acute and chronic fear. It also attempted to study the relationship between changes in gastric acidity and in blood sugar levels. The need for such an experiment arises from a previous study of chronic fear and hydrochloric acid secretion in dogs, from considerations of the applicability of Cannon's emergency hypothesis to. chronic emotions and the psychosomatic disorders, and from considerations of the etiology of peptic ulcer.In a previous experiment (26) the gastric acidity and heart rate of dogs were measured during control conditions and during a modified conditioning procedure designed to produce chronic fear behavior. Considering the group of dogs as a whole, the experimental procedure resulted in chronic fear behavior and a significant increase in both the gastric acidity and the non-resting heart rate.Cannon s theory of the emergency function of emotions (10) states that during rage and fear physiological changes occur which in general are a result of discharge over the sympathetic-adrenal division of the autonomic nervous system and simultaneous inhibition of the parasympathetic division. The resulting pattern of autonomic changes is regarded as the normal autonomic effector pattern of fear or anxiety, rage, and anger in an acuteemergency situation.Although the emergency theory was originally based on studies of acute responses, this