The suggestion that migraine is sometimes a phenomenon of protein sensitization is not new. The concurrence of this disease with asthma, urticaria and hay-fever either in one individual or in one family was first mentioned long ago. Many contributions have presented indirect evidence tending to substantiate this hypothesis, but I have not discovered any description of cases or of experimental work in which the cause was discovered, the disease relieved by the removal thereof and caused to return, following the reapplication of the etiologic factor. In allergy this roughly parallels Koch's postulates as applied to bacteriology, and is a necessary antecedent to acceptance of the theory. As early as the first half of the ninteenth century migraine was grouped by some, particularly members of the French school, such as Trousseau, Bouchard and Dieulafoy, with asthma, eczema, epilepsy, gout and lithiasis, and these conditions together constituted the manifestations of the lithemic