Investigation of Middle Indian morphology from the strictly linguistic point of view can fairly be said to have been made thus far only by Jules Bloch, notably in his L'Indo-aryen du Véda aux temps modernes (Paris, 1934). However valuable as descriptive grammars and as collections of material the Grammatik der Prakrit-Sprachen of Richard Pischel (Strasbourg, 1900) and the Pāli Literatur und Sprache of Wilhelm Geiger (Strasbourg, 1916) undoubtedly are, both works are far from linguistic in purpose. In Bloch's masterly survey of the history of Indian linguistic development from Vedic through Sanskrit and Middle Indian to Modern Indian, on the other hand, embracing phonology, morphology, and sentence-structure, it was scarcely possible, in view of the mass of material, for him todiscuss every detail. It is my purpose, then, as a comparative linguist, to consider in the following pages certain phenomena in Middle Indian which seem to merit further study, omitting on principle all that appears already to have been satisfactorily explained, such as the pronouns (cf. Bloch, pp. 145–7). Speaking in very general terms, Middle Indian would seem to present a mixture of forms common to Vedic and Sanskrit, number of survivals to be paralleled only in Vedic or Iranian, and a considerable amount of contamination of formations whose functions were, at least approximately, identical.