Fig. 43, after Starr, shows how the fibres run downwards. All sensory currents entering the hemispheres run out from the Rolandic region, which may thus be regarded as a sort of funnel of escape, which narrows still more as it plunges beneath the surface, traversing the inner capsule, pons, and parts below. The dark ellipses on the left half of the diagram stand for hemorrhages or tumors, and the reader can easily trace, by following the course of the fibres, what the effect of them in interrupting motor currents may be. [Illustration: FIG. 43.--Schematic transverse section of the human brain, through the rolandic region. _S_, fissure of Sylvius; _N.C._, _nucleus candatus_, and _N.L._, _nucleus lenticularis_, of the corpus striatum; _O.T._, thalamus; _C_, crus; _M_, medulla oblongata; _VII_, the facial nerves passing out from their nucleus in the region of the _pons_. The fibres passing between _O.T._ and _N.L._ constitute the so-called internal capsule. ] One of the most instructive proofs of motor localization in the cortex is that furnished by the disease now called aphemia, or _motor aphasia_. Motor aphasia is neither loss of voice nor paralysis of the tongue or lips. The patient's voice is as strong as ever, and all the innervations of his hypoglossal and facial nerves, except those necessary for speaking, may go on perfectly well. He can laugh and cry, and even sing; but he either is unable to utter any words at all; or a few meaningless stock phrases form his only speech; or else he speaks incoherently and confusedly, [Illustration: FIG. 44.--Schematic profile of left hemisphere, with the parts shaded whose destruction causes motor ('Broca') and sensory ('Wernicke') aphasia.]