These chemical changes in the secretion of the mucous membranes, together with the excess of uric acid would seem to point either to a general perversion of the secretory mechanism or to a deficient elimination, or to both. The periodic occurrence may be accounted for by assuming that the systemic strain is sufficient to initiate the symptoms. The fact that the attack is actually delayed or hastened in susceptible individuals by the late or early beginning of hot weather, and that these cases get relief by going to a more moderate climate is further evidence of this. Again we are reminded of Dr. Still’s teaching, that the body maintains its own chemical laboratory which adjusts or tends to adjust its work to the needs of that body, but under abnormal strain this adjustive mechanism may fail to meet all of the demands of function. It seems here that the osteopathic concept may easily include all environmental causes as well as internal causes in the predisposition to deficient function or disease. =Structural Pathology.=—During the attack there is a general catarrhal inflammation of all nasopharyngeal membranes, accompanied by a watery discharge and marked swelling of the turbinates. Sensitive areas may be found on the middle turbinate and opposite wall of the septum. Probably it is this hypersusceptibility to irritation that causes the attack from the air-borne irritants. The pseudo-membrane which may be found covering a part or all of the mucous membranes of the nares probably results from this irritation and is formed for the purpose of protection. =Clinical Types.=—Clinically, three rather indefinite types of hay fever may be recognized, viz.: Vernal, those cases which have their attack sometime during May, June or July; Autumnal, in which the attack occurs in August or September and usually lasts until the beginning of cold weather, and an indefinite or pseudo form occurring at any time of the year, with no characteristic attack, as in the other forms, but with indefinite symptoms resembling hay fever. =Symptoms and Diagnosis.=—Patients usually go to the physician self diagnosed. The characteristic sneezing, the watery discharge from the nose, and the irritation of all membranes of the nasopharynx and conjunctiva will serve to make a diagnosis in most cases. Direct examination will reveal the nasal congestion and other characteristic pathology as described above. =Termination.=—Most cases of the autumnal form, unless successfully treated, continue with equal or increased severity until after the first or second frost, when they usually terminate in asthma, bronchitis or sinuitis, which lasts for several weeks or months. Each year the attack lasts longer and is more severe and the asthma occurs earlier and is more severe. Treatment