THREE FIGURES
INTRODUCTTON
As part of a more extensive study 011 the various afferent systems impinging upon the cerebellum (Snider and Stowell, '44), it became necessary to learn more about the widespread connections of the inferior olive to that organ. Onr task was greatly simplified by the timely appearance of tlie cxcellent contribution by Brodal ( '40), who showed localized relatioilships between the olive and the cerebellum. To understand this system it becomes imperative to know the afierents to tlie olive. The thalamo-olivary tract of the text books has been doubted by many ~o r k e r s (see Mettler, '44). Tlie annuloolivary tract of Mettler ('44), the medial tegmental tract of Ogawa ( '39), and the pallido-incerto-tegmento-olivary tract of Woodburne, Crosby and McCotter ('46) need verification by a different technique.
This research was given financial aid by the Office of Naval Research.
a This paper was in manuscript form before the authors had tlie plcasiire of reading Dr. W. J. C. Verbaart's (this jonrnal) paper. It is gratifying to note that he was able to follow the central tegmental tract to the olive in both inan and monkey. This is in close agreement with onr electrical studies on the cat niid monkey.