1. A generation or two ago the writers of handbooks of Indo-European comparative grammar were for the most part considerably more definite in their conclusions regarding the form of the parent speech than their successors are today.l This is particularly true with regard to the verbal system. In those days the repertoire of verb categories was based largely on the agreements between Greek and Sanskrit, some of which were indeed striking, and the deviations of the other Indo-European languages were explained as developing out of that skeletal system, or as innovations, or were left without explanation.2 There were, of course, a great many one-man rebellions against this GrecoIndian autocracy, but they had little effect on general opinion until the discovery of Hittite. After the Hittite verb had been analyzed and acquaintance with it became public property, a great many more scholars, raised on the Brugmann system as I was, paused to think; and the longer they thought, the more uncertain they became. The great simplicity of the Hittite system, in spite of all its irregularities, its two conjugations, the mi and the bi, its two simple tense formations, present and preterit, its two moods, indicative and imperative, its loosely constructed and confusingly elaborate medio-passive, could hardly be derived from the formally strict system as depicted by Greek and Sanskrit. Then, to add to the disturbance of time-honored beliefs, another new IndoEuropean language appeared: Tocharian. On the face of it, from a mere survey of Tocharian verbal categories, it did not at first seem so upsetting; for we have here about a usual number of verbal form classes: indicative, subjunctive, optative; present, imperfect, and preterit (in the indicative); active and mediopassive in all moods and tenses. But a closer examination shows, except for a few present-stem formations, very little agreement in form and function with the older preconceived system. Of course Tocharian could not compete with Hittite in the authority of antiquity, since it is a medieval language, chronologically on a par with the earlier Germanic dialects. Yet, in my opinion, if there is one place where Tocharian can make a contribution to our knowledge of IndoEuropean, it is through a study of its verbal system in comparison with those of the other Indo-European languages, not merely with Greek and Sanskrit, but also and especially with other languages of the family to which less authority was granted by Brugmann and his followers in determining the state of the parent speech.