=Osteopathic Lesions.=—Osteopathic lesions, such as interosseous, muscular and ligamentous, seem to function as predisposing causes by their general effects upon the system. It seems probable that their effects upon the organs of metabolism and elimination are of greater importance than any direct or specific effect in causing the immediate symptoms. In practically all cases lesions of the upper thoracic vertebræ and ribs and of the cervical region are present. It is my opinion that such lesions are more often secondary than primary. =Respiratory Reflex Inefficiency.=—Measurement of nerve force in these cases shows that none are really possessed with “an excess of nerve force,” but that practically all vary from two-thirds to four-fifths normal, showing that probably all cases are deficient in nerve force. This instability of the nervous system can be explained, I believe, in the theory of peripheral reflex insufficiency. As evidence of this the following facts may be cited: 1. It is known that peripheral irritation of almost any nature, to the mucous membranes of the nasopharyngeal tract, will excite an attack in susceptible individuals. 2. That any treatment which tends to increase the resistance of these membranes will prevent or relieve an attack. 3. That peripheral inhibition to these surfaces will temporarily relieve an attack. 4. That complete normalization of these membranes will make the patient resistive to the so-called specific irritants, such as pollen, dust, etc. 5. That the mucous membranes of the entire respiratory and gastro-intestinal tract react to irritants to bring about “the hay fever state” and that any treatment which tends to normalize these membranes, renders the patient more resistive to hay fever attacks. =Exciting Causes.=—There is no doubt that various air-borne irritants, such as pollen, dust, chemical fumes, emanations from animals, etc., act as exciting causes of acute attacks, and yet there are cases that develop acute attacks out of season or at a time when it seems that there could be no air-borne irritation. From evidence which will be offered later (see prognosis) I am led to believe that probably all susceptible cases can be made entirely resistive to the air-borne irritants. Pathology =Functional Pathology.=—Certainly in this disease there is ample evidence of marked perversions of function or functional pathology. Kyle believes that in many cases the cause of local irritation lies in “some chemical change in the constituents of the mucus-secreting glands,” and “it is a well known fact that in many cases of hay fever the irritation is not limited to the nasal mucous membrane. The eyes and mucous membrane of the stomach and bladder, and even the intestines may be markedly irritated.”