IOO THE CEREBRUM. 



Motor Fibers. The inferior lamina of the internal capsule 

 contains most of the temporo-pontal tract (tractus cerebro- 

 cortico-pontalis temporalis] which extends from the temporal 

 cortex beneath and behind the lentiform nucleus to the nucleus 

 of the pons and nuclei of the motor cerebral nerves. The inter- 

 mediate tract (tractus intermedius] rises in the lentiform nucleus 

 and runs through the anterior part of the inferior lamina, in its 

 course to the substantia nigra and nucleus pontis in which it 

 terminates. 



Sensory Fibers (Figs. 32, 33 and 70). The following sensory 

 fibers are found in the inferior lamina, viz., the ventral stalk 

 (ansa peduncularis) of the thalamus (common sensory) running 

 from the thalamus chiefly to the somsesthetic cortex; and part 

 of the acustic or temporo-thalamic .radiation (special sensory), 

 which extends from the medial geniculate body to the auditory 

 cortex in the superior and transverse temporal gyri. In part at 

 least the ventral stalk rises from nuclei lower down than the thal- 

 amus from the substantia nigra and the nuclei of the gracile 

 and cuneate columns probably. The fibers of the ventral stalk 

 of the thalamus are separated into an upper and a lower lamina 

 by a thin sheet of gray substance. The lower lamina (inferior 

 peduncle of the thalamus) runs for the most part beneath the 

 lentiform nucleus into the external capsule and terminates in the 

 temporal lobe and the island. The upper lamina (ansa lenticu- 

 laris) enters the lentiform nucleus in two vertical sheets that separate 

 the three zones of that nucleus. Its fibers to a large extent ter- 

 minate in the lentiform nucleus, whose axones continue the path 

 through the parietal stalk, in the superior lamina of the capsule, 

 to the somaesthetic area of the cortex. In the angle between the 

 inferior horn and the central part of the lateral ventricle, the 

 inferior lamina joins the superior. 



The superior lamina (or superior ramus) of the internal 

 capsule contains most of the basis pedunculi (Fig. 30). It is a 

 thick and strong sheet of fibers. Often it is considered as the 

 entire "internal capsule," the inferior lamina being disregarded. 

 The superior lamina extends, fan-like, from the basis pedunculi to 

 the lateral extremity of the corpus callosum, with which it inter- 



