[Illustration: The drawing exhibits the cerebral connection of all the cerebral nerves except the first. It is from a sketch taken from two dissections of this part. D. Posterior optic tubercle. The generative bodies of the thalamus are just above it. E. Cerebellum. H. Spinal cord. I. Tuber cinereum. K. Optic thalamus divided perpendicularly. W. Corpus restiforme. X. Pons Varolii. _b b._ Optic nerves: this nerve is traced on the left side back beneath the optic thalamus and round the crus cerebri. It divides into four roots; the first (_g g_) plunges into the substance of the thalamus, the next runs over the external geniculate body and surface of the thalamus, the third goes to the anterior optic tubercle, the fourth runs to D, the testis or posterior optic tubercle. C. Third pair common oculo-muscular, arising by two roots like the spinal roots of the spinal nerves, the upper from the gray neurine of the locus niger, the lower from the continuation of the pyramidal columns in the crus cerebri and Pons Varolii, _p t_. _d_, Fourth pair, apparently arising from the inter-cerebral commissure (I _c_), but really plunging down to the olivary tract (_o t_) as it ascends to the optic tubercles. _e m._ Motor or non-ganglionic root of the fifth pair, arising from the posterior edge of the olivary tract. _e._ Sensory root of the fifth pair running down between the olivary tract and restiform body to the sensory tract. _f._ Sixth pair, or abducens, arising from the pyramidal tract. _g._ Seventh pair, facial nerve, or portio dura, arising by an anterior portion from the olivary tract and by a posterior portion from the cerebellic fibers of the anterior columns as they ascend on the corpus restiforme, W. _h._ Eighth pair, portio mollis, or auditory nerve, with its two roots embracing the restiform body. _i._ Ninth pair, or glosso-pharyngeal; and _j._ Tenth pair, or par vagum, plunging into the restiform ganglion. J J. Fibers of the optic nerve plunging into the thalamus; immediately below these letters is the corpus geniculatum externum. _k._ Eleventh pair, or lingual nerve; the olivary body has been nearly sliced off and turned out of its natural position; some of the filaments of the lingual nerve are traced into the deeper portion of the ganglion, which is left in its situation; others which are the highest are evidently connected with the pyramidal tract.]