INTERLACEMENT OF THE CEREBELLAR PEDUNCLES. 473 



The transverse fasciculi that proceed in Man from the corpus 

 restiforme at the plane of origin of the nervus facialis imme- 

 diately behind the deep layer of transverse fibres of the pons, 

 and extend partly in front of, and partly through, the trans- 



Fig. 256. 



Fig. 256.* Transparent transverse section of the medulla oblongata 

 of Hypsiprimnus murinus, at the level of origin of the auditory nerve, 

 vin, Auditory nucleus ; P, pyramid ; MF, transverse section of the 

 motor area of the posterior division of the medulla oblongata ; H t 

 raphe ; G', gelatinous substance ; 0, superior olivary body ; Kl, in- 

 ternal division of the peduncle of the cerebellum (processus e cere- 

 bello ad medullam, Kleinhirnstiel) ; T, corpus trapezoides ; 5, genu 

 of the facial nerve ; 6, nervus abducens ; 8, root of the auditory nerve ; 

 8', fasciculi from the nucleus of the auditory nerve which are lost in 

 the transverse section of the posterior longitudinal fasciculus, 8". 



verse section of the fifth, so as, after decussating with the 

 layers of the fillet, to reach the raphe (fig. 254, cr through S to 

 H) are identical with the fasciculi of the corpus trapezoides 

 (Deiters) which are exposed to view close to the transverse 

 section of the pyramids in animals, on account of the shortness 

 of the pons (figs. 256, T, 255, St, Rs). After decussating in the 

 median raphe' of the posterior tract of the cerebral peduncle, 

 they run behind the corpus trapezoides of the other side again 

 outwards, and reach the superior olivary body (fig. 255, 

 N 0; figs. 254 and 256, E0). Through a spiral invo- 

 lution of the surface of this centre they assist in the for- 



* Inasmuch as the representation of anatomical systems does not follow 

 planes of section, figs. 256 and 257 are removed from the sequence they 

 would naturally occupy if the successive planes were alone considered ; 

 but, in order that the reader may connect the appearances presented by 

 the successive sections, the figures are numbered in accordance with this 

 succession. 



