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. Diseases of the nervous system . ti-cally; above it is the sulcus paracentralis. Among the anterior convolutions on the median surface of the hemispherewe find the gyrus frontalis superior and a few of its subdivisions, then theone mentioned above, the lobulus paracentralis, which corresponds to the cen-tral convolutions between the sulcus paracentralis and the ascending portionof the sulcus calloso-marginalis behind the precuneus, it is of a square form,and reaches posteriorly to the parieto-occipital fissure. This is joined dorsallyby the triangular cuneus between the last mentioned furrow
. Diseases of the nervous system . ti-cally; above it is the sulcus paracentralis. Among the anterior convolutions on the median surface of the hemispherewe find the gyrus frontalis superior and a few of its subdivisions, then theone mentioned above, the lobulus paracentralis, which corresponds to the cen-tral convolutions between the sulcus paracentralis and the ascending portionof the sulcus calloso-marginalis behind the precuneus, it is of a square form,and reaches posteriorly to the parieto-occipital fissure. This is joined dorsallyby the triangular cuneus between the last mentioned furrow and the fissuracalcarina, the anterior point of which runs as the pedicle of the cuneus to theisthmus gyri fornicati; finally we observe the gyrus descendens which passesdownward behind the fissura calcarina to the gyrus lingualis, which was de-scribed when outlining the temporal lobe. A brief description of the island must be given. The island of Reil iscovered by the surrounding portions of the brain, and externally immediately. Fig. 6.—Longitudinal Section through the Middle of the Human Brain. (After Edinger.) adjoins the ganglia of the cerebrum. Around this structure runs the sulcuscircularis Reilii; anteriorly and ventrally the island passes into the freestructure at the base of the brain, and at the limen insula? directly into thelamina perforata anterior. A permanent sulcus, the sulcus centralis insula?,divides the island into two lobes; the larger anterior (pars frontalis) pos-sesses three to four gyri breves, the smaller posterior (pars parieto-occipitalis)has one to two gyri longi which pass to the temporal pole. The region ofthe island, which is especially developed in man as the association region ofhuman speech, shows in animals a gradually ascending development. Waldeyerfound in his investigations of the brain of anthropomorphic apes that theconstruction of the island in the monkey is fundamentally the same as inman; there is first an arching convolution with
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectnervoussystem, bookye