Chap, ii.] 



THE BRAIN. 



757 



frontal district of the motor region, take up their position at the 

 knee of the internal capsule ; and the portion destined for those 

 upper cervical nerves which carry out movements of the head 

 through the muscles of the neck, starting from the extreme 

 frontal and dorsal parts of the area, is also apparently directed 

 to the knee of the capsule. The rest of the tract, starting from 

 the part of the area lying at once behind and mesial to the above, 

 occupies in the capsule a position posterior to them in the hind 

 limb of the capsule ; and it will be observed that the tract for 

 the fore limb which begins on the surface lateral of the tracts 

 for the trunk and hind limb, shifts its course in relation to theirs, 

 so that in the capsule it is in front of them, not lateral to them. 



n.f.t. 



Fig. 132. Through the Bulb just behind the Pons. (Sherrington.) 

 Taken in the line 110, Fig. 108. 



Py. Pyramids. B. Restiform Body. Cbm. cerebellum. F. Fillet. /. a. e. 

 external, /. a. i. internal arcuate fibres, t. bundle of fibres from olive to the 

 lenticular nucleus. I. posterior longitudinal bundles, n. f. t. nucleus of fasci- 

 culus teres, s. o. superior olive, n. c. e. nucleus centralis (the marks within it 

 are sections of bundles of fibres by which it is traversed), s. g. substance of 

 Rolando. 



V. a. ascending root of fifth nerve. VII. n. nucleus of the 7th nerve. VIII. 

 auditory nerve, chiefly the dorsal or cochlear root ; VIII. a. medium nucleus, VIII. 

 p. lateral nucleus, VIII. }. accessory nucleus of auditory nerve. IX. fibres of 

 root of ninth nerve passing through ascending root of fifth nerve. 



It may further be observed that while in the tracts for the trunk 

 and hind limb the same fore and aft order which obtains on 

 the surface is reproduced in the capsule, even apparently to the 

 strange precedence of the ankle over the knee, the order of the 

 several elements in the fore limb tract which is lateral on 

 the surface becomes regularly fore and aft in the capsule. In 

 the capsule the several elements are arranged in a linear order, 

 corresponding broadly to that of the distribution of the muscles 

 along the longitudinal axis of the body ; on the cortex they are 

 disposed in an order the cause of which is at present not very 



