232 THE CEREBRUM. 



arrive in the lateral nucleus of the thalamus. In the capsula 

 interna the corticipetal projection fibers constitute the cortical 

 fillet and the optic and acustic (and gustatory?} radiations. The 

 former end in the somaesthetic area of the cerebral cortex, the 

 latter in the visual, auditory and gustatory cortex. 



The olfactory projection fibers are contained neither in the 

 tegmentum nor in the internal capsule. They proceed from the 

 olfactory bulb, through the olfactory tract and its striae, directly 

 to the cerebral cortex. 



The exact origin of the cortical fillet (Figs. 70 and 71) has 

 not been entirely determined, but it is known to rise, chiefly, 

 in the lateral nucleus of the thalamus. The ventral stalk of the 

 thalamus (Fig. 70) runs through the internal capsule, in the inferior 

 lamina. It is relayed largely hi the globus pallidus. Its fibers 

 enter the medullary laminae of the nucleus lentiformis and the 

 external capsule; ultimately they terminate in the upper one- 

 third of the posterior central gyrus and in the temporal and insular 

 lobes (see p. 212). From the anterior end of the thalamus streams 

 a great pencil of fibers, called the frontal stalk (Fig. 70). It mingles 

 to a small extent with the fibers of the pyramidal tract, but runs 

 chiefly through the frontal part of the internal capsule. Its 

 termination is largely in the corpus striatum; some of its fibers 

 reach the frontal cortex. 



The parietal stalk issues from the lateral surface of the thala- 

 mus higher up than the ventral stalk and mingles with the pyram- 

 idal fibers in the superior lamina of the internal capsule. Its 

 location is principally in the posterior third of the occipital part 

 of the capsule (Figs. 70 and 71). It terminates in the para- 

 central lobule and the posterior central gyrus. According to 

 Flechsig some fibers also end in the upper extremity of the anterior 

 central, the superior frontal gyri and in the underlying part of 

 the gyrus cinguli. The parietal stalk, if we may apply this name 

 to all the common sensory fibers in the occipital part of the capsule, 

 ultimately comprises all the corticipetal fibers to the somaesthetic 

 area. Flechsig gives their origin and termination, in the order 

 of their medullation, as follows: 



a. The alpha bundle, a small one, runs from the globus pal- 



