Henry Gray (18251861). Anatomy of the Human Body. 1918.
anterior, raised part, the culmen or summit, and a posterior sloped part, the clivus; the quadrangular lobule is similarly divided. The culmen and the anterior parts of the quadrangular lobules form the lobus culminis; the clivus and the posterior parts, the lobus clivi.
The Folium Vermis and Superior Semilunar Lobule.The folium vermis (folium cacuminis; cacuminal lobe) is a short, narrow, concealed band at the posterior extremity of the vermis, consisting apparently of a single folium, but in reality marked on its upper and under surfaces by secondary fissures. Laterally, it expands in either hemisphere into a considerable lobule, the superior semilunar lobule (lobulus semilunaris superior; postero-superior lobules), which occupies the posterior third of the upper surface of the hemisphere, and is bounded below by the horizontal sulcus. The superior semilunar lobules and the folium vermis form the lobus semilunaris.
The under surface of the cerebellum(Fig. 703) presents, in the middle line, the inferior vermis, buried in the vallecula, and separated from the hemisphere on either side by a deep groove, the sulcus valleculæ. Here, as on the upper surface, there are deep fissures, dividing it into separate segments or lobules; but the arrangement is more complicated, and the relation of the segments of the vermis to those of the hemispheres is less clearly marked. The inferior vermis is subdivided from before backward, into (1) the nodule, (2) the uvula, (3) the pyramid, and (4) the tuber vermis; the corresponding parts on the hemispheres are (1) the flocculus, (2) the tonsilla cerebelli, (3) the biventral lobule, and (4) the inferior semilunar lobule. The three main fissures are (1) the postnodular fissure, which runs transversely across the vermis, between the nodule and the uvula. In the hemispheres this fissure passes in front of the tonsil, crosses between the flocculus in front and the biventral lobule behind, and joins the anterior end of the horizontal sulcus. (2) The prepyramidal fissure crosses the vermis between the uvula in front and the pyramid behind, then curves forward between the tonsil and the biventral lobe, to join the postnodular fissure. (3) The postpyramidal fissure passes across the vermis between the pyramid and the tuber vermis, and, in the hemispheres, courses behind the tonsil and biventral lobules, and then along the lateral border of the biventral lobule to the postnodular sulcus; in the hemisphere it forms the anterior boundary of the inferior semilunar lobule.
The Nodule and Flocculus.The nodule (nodulus vermis; nodular lobe), or anterior end of the inferior vermis, abuts against the roof of the fourth ventricle, and can