XXXIl] THE SPINAL BULB 259 



Numerous transverse bundles of fibres between the pyramids 

 and the fillet, and through the fillet itself the trapezium fibres, 

 sometimes called the deep fibres of the pons. 



Running from the 6th nerve may be seen obliquely cut root 

 fibres, running ventrally and a little laterally (they run back- 

 wards in the dorsal part of the pons fibres). 



9. Section through the outgoing fibres of the 7th nerve and 

 the anterior part of the 6th nucleus. The ascending bundle 

 of the 7th nerve near the raphe is large, fibres proceed from it 

 and curve dorsally over the 6th nucleus ; more laterally a large 

 bundle of the outgoing 7th is seen and perhaps running out 

 between the descending 5th and the upper olive. 



Medially of the outgoing root is the 7th nucleus with fibres 

 running dorsally (they pass through the 6th nucleus to the 

 ascending 7th). 



From the medial border of the 6th nucleus run fibres of 

 the 6th nerve. 



The dorsal part of inner division of the restiform body is at 

 the side of 4th ventricle and has large nerve cells in it 

 Bechterew's nucleus. 



Fillet, trapezium, pons, bulbar 5th, nucleus dentatus, are 

 much as in 8. 



In a section taken a little farther forward the nuclei of the 6th 

 and 7th nerves will be' absent, but the ascending fibres of the 7th will 

 be seen curving out ; forming the genu. 



D9' 7, 8, 9. Owing to the comparatively small development 

 of the middle peduncle of the cerebellum in lower animals, the 

 arrangement in this region is more easily followed than in man. 



Section through the trapezium. There are no superficial pons 

 fibres. The upper olive is present; it is seen in the ventro-lateral 

 region as a rod and an S-shaped piece of grey substance. 



The accessory nucleus of 8c. and Deiter's nucleus are distinct. 

 Between the ace. nuc. of the two sides are numerous bundles of fibres, 

 the trapezium, running between the fibres of the fillets and dorsally 

 of the pyramids. 



17-2 



