646 



STRUCTURE OF THE CEREBRUM. 



[CH. XLVI. 



enter for the supply of the basal ganglia, and these are liable to 

 become diseased, and if they rupture, a condition called apoplexy 

 is the result ; if the haemorrhage is excessive, death may occur 

 almost immediately ; but if the patient recovers, a condition of 

 more or less permanent paralysis remains behind ; and a very 

 large amount of paralysis results from a comparatively limited 

 lesion, because so many fibres are congregated together in -this 

 narrow isthmus of white matter. If the haemorrhage is in the 



t'ig. 479. Diagram to show the connection of the Frontal Occipital Lobes with the Cere- 

 bellum, &c. The dotted lines passing in the crusta (T.OC), outside the motor fibres, 

 indicate the connection between the temporo-occipital lobe and the cerebellum. F.C., 

 the fronto-cerebellar fibres, which pass internally to the motor tract in the crusta ; 

 i. F., fibres from the caudate nucleus to the pons. Fr., frontal lobe; Oc., occipital 

 lobe ; AF., ascending frontal ; AP.. ascending parietal convolutions ; PCF., precentral 

 fissure in front of the ascending frontal convolution ; FR., fissure of Rolando ; IFF., 

 interparietal fissure. A section of erus is lettered on the left side. s.N.,8ubstantianigra; 

 PY., pyramidal motor fibres, which on the right are shown as continuous lines converging 

 to pass through the posterior limb of i.e., internal capsule (the knee or elbow of which 

 is shown thus *) upwards into the hemisphere and downwards through the pons to 

 cross at the medulla in the pyramidal decussation. Ijif, crossed pyramidal tract ; 

 apt, direct pyramidal tract. (Gowers.) 



anterior part of one internal capsule, motor paralysis of the 

 opposite side of the body (hemiplegia) will be the most marked 

 symptom. If the haemorrhage occurs in the posterior part, sen- 

 sory paralysis of the opposite side of the body will be the most 

 marked symptom. If the motor-fibres are affected, degeneration 

 will occur in the pyramidal tract and can be traced through the 

 pes of the crus and mid-brain to the pyramid of the pons and 

 bulb, and then in the crossed pyramidal tract of the opposite side 

 and in the direct pyramidal tract of the same side of the cord. 



