3GO 



with nerve-cells similar in appearance to those of the inner nucleus. 

 The nerve is also reinforced by fibres radiating from the centre of 

 the restiform body as it winds round the latter. The anterior divi- 

 sion of the auditory nerve consists of two portions : the principal 

 portion penetrates the medulla beneath the restiform body, and, 

 running along the outer side of the caput cornu, enters both parts 

 of the auditory nucleus ; the other portion runs backward along 

 the upper border of the restiform body, which it accompanies over 

 the superior peduncle to the inferior vermiform process of the cerebel- 

 lum. The outer portion of the auditory nucleus, consisting of the 

 posterior pyramid and its vesicular network, is also ultimately thrown 

 backward into the cerebellum, part of it arching over the fourth ven- 

 tricle to the opposite side, while the rest extend outward to the corpus 

 dentatum. The corpus dentatum is grasped, as it were, by an expan- 

 sion of the restiform body, which bends backward after entering the 

 cerebellum. 



It would be useless in this place to attempt an intelligible descrip- 

 tion of the complicated course of the fibres in the human pons Varolii ; 

 but I may observe, that at its lower portion I find a structure in 

 every sense homologous with that which in Mammalia is called the 

 trapezium. It is not, however, situated below, but within the pons, 

 of which it forms the most posterior of the transverse fibres. These 

 transverse or arciform fibres proceed out of the restiform bodies and 

 auditory ganglia, and sweep round the extremity of the caput cornu 

 to the back of the anterior pyramids to decussate across the raphe. 

 As they pass the ganglion, or auditory nerve, they receive fibres from 

 it. On each side, where, in animals, it forms a rounded projection, 

 it contains a very peculiar vesicular nucleus, which has a convoluted 

 appearance and structure, resembling another olivary body. These 

 nuclei, which were first pointed out by myself in 1857 (Proceedings 

 of Royal Society), and subsequently by Prof. Schroder V. der Kolk, 

 first make their appearance much lower down in the medulla, at 

 the point where the other olivary bodies begin to diminish, as two 

 cylindrical columns of large nerve-cells with bundles of longitudinal 

 fibres. On reaching the trapezium, the cells become much smaller, 

 and are arranged in convoluted laminae. They are larger in animals 

 than in Man, and are particularly developed in the Cat. Through 

 the trapezium the facial nerve passes transversely backward and 



