. Quain's elements of anatomy . s ventrally of transverse or commissmal fibres, betweenwhich the longitudinal fibres prolonged upwards from the medulla ob-longata pass ; together with a large intermixture of grey matter. Thesuperficial fibres on the ventral surface (fig. 272, po) are transverse intheir general direction, but while the middle fibres pass directly across,the lower set ascend slightly, and the superior fibres (fig. 271,«), whichare the most curved, descend obliquely to reach the crus cerebeUi on eachside ; some of the upper fibres cross obliquely the middle and lower 300 THE CEEE
. Quain's elements of anatomy . s ventrally of transverse or commissmal fibres, betweenwhich the longitudinal fibres prolonged upwards from the medulla ob-longata pass ; together with a large intermixture of grey matter. Thesuperficial fibres on the ventral surface (fig. 272, po) are transverse intheir general direction, but while the middle fibres pass directly across,the lower set ascend slightly, and the superior fibres (fig. 271,«), whichare the most curved, descend obliquely to reach the crus cerebeUi on eachside ; some of the upper fibres cross obliquely the middle and lower 300 THE CEEEBULLUM AND PONS. ones, so as to conceal them at the sides. When the superficial trans-verse fibres are removed, the prolonged fibres of the anterior pyramidscome into view ; these, as they ascend through the pons, are separatedinto smaller bundles (figs. 272, 273, 274, j??/), intersected by other trans-verse white fibres, which, with those upon the surface, are all continuedinto the middle peduncle of the cerebellmn. Fig. Fig. 271.—View op the anterior surfaceOF THii PONS Varolii and medulla oblon-gata, WITH A SMALL PART OF THE SPINALCORD ATTACHED a, a, pyramids ; 0, their decussation; c, c,olives ; d, d, restiform bodies ; e, external arci-form fibres, curving round the lower end of theolive; /, fibres described by Solly as passing fromthe anterior column of the cord to the cere-bellum ; g, anterior column of the spinal cord ;h, lateral column ; 2^> pons Varolii; i, its upperfibres ; v, v, roots of the fifth pair of nerves. At the lower part of the pons, behindthe fibres from the anterior pyiamids,is a special set of transverse fibres (:, 23, fig. 272, t), named the frajje-ziimi—so called because in most of thelower animals, in which the more veu-trally situated fibres of the pons are notdeveloped and the pyramids are small,these transverse fibres partially appearon the surface between the pyramid-bundles in an area of a somewhatfour-sided shape. Laterally
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