THE SUBTHALAMIC REGION, ETC. 



119 



brain, for, if the second part is interrupted, there can no longer 

 be a voluntary motion of any kind. In a case of apoplectic 

 rupture of the internal capsule the muscles of the opposite side 

 of tlu body are not really paralyzed ; they simply cannot be 

 made to contract by the will. This, however, can readily be 

 accomplished by other forms of stimulation. It is otherwise in 

 a case, for instance, of infantile paralysis, where a nerve-nucleus 

 itself is destroyed. In this case we have a true paralysis, gener- 

 ally irremediable, which leads to atrophy, and the muscles 



FIG. 69. 



Longitudinal section through the quadrigeminal region of a human embryo of 28 

 yreeks, near the median line. The outer wall of the aqueduct of .Sylvius has been cut 

 into. Termination of the fasciculus longitudiualis posterior in the nucleus of the oculo- 

 motor. All medullary fibres stained with hseiiiatoxylin. 



Hint. LiingibUmlel, Posterior longitudinal faacitmltu. Him*elinkel, PeUuneulus cerebri. 



VierhUytlplatte, Quodrigeminal lamina. 



respond very little, if at all, to reflex or any other stimulation. 

 It makes a great difference, so far as the prospect of a restora- 

 tion of function is concerned, whether the cerebral or the deeper 

 portion of the innervation tract is affected. 



The diagram Fig. 68 is an attempt to represent the most important fibres 

 passing to the nucleus of a cranial nerve. Besides the above-described central 

 tract, the nucleus, and the peripheral tract, you will notice fibres connecting the 

 nerve-nucleus with deeper-lying nuclei of other nerves, and, in addition to these, 

 still other fibres arising from the nucleus, but emerging from the central organ in 

 the nerve of the opposite side. 



