74 EXPLANATION OF TUE PLATES. 



PLATE XI. 



Pig. 39. One of the convolutions of the lamina of the human olivary body, from a longitudinal 

 section, magnified 120 diameters, showing the cells of the lamina and their relations to the fibres. A, 

 fibre-bundle penetrating the convolution, sending out its fibres among the cells : £, B, bundle surround- 

 ing the fold of the lamina : C, G, bundles passing from the central bundle A through the lamina towards 

 distant convolutions : Z>, a few scattered cells of the neighboring convolutions. 



Fig. 40. Transverse section through the hypoglossal and vagal nuclei, from the sheep, magnified 20 

 diameters, some details being subsequently added with higher powers. A, A, A, the hypoglossal 

 roots : B, the raphfe : X, the apex of the fourth ventricle : F, the vagus roots : D, bundles derived 

 from the vagus, sweeping round the margin of the hypoglossal nucleus on their way to the raphe, 

 where many of them decussate with those from the opposite side : H, longitudinal fasciculi : b, group 

 of cells situated in the anterior portion of the hypoglossal nucleus, in close connection with the hypo- 

 glossal roots and with the marginal fibres derived from the vagus. This group is represented in Fig. 

 31. c, marginal fibres derived from the vagus, passing to some extent into the antero-lateral columns : 

 m, m, fibres derived fi'om the hypoglossal roots curving backwards towards the posterior part of the 

 nucleus : e, po.sterior commissure, on the edge of which is seen the epithelial layer : li, posterior Cells 

 of the hypoglossal nucleus : u, cells of the vagus nucleus. 



PLATE XII. 



Fig. 41. Group of cells from the auditory nucleus of the cat, magnified 120 diameters; from a 

 transverse section near the entrance of the auditory root. A, A, A, fibres derived from the auditory 

 root, some of which may be tra'ced towards cells: B, curved fibres and bundles, some of which are 

 derived from the root, radiating into the antero-lateral network : C, fibres coming down from the 

 cerebellum. 



Fig. "42. Upper olivary body of the cat, from a transverse section, magnified about 20 diameters. 

 F, part of the facial root : A, A, bundles from the external arciform plexus : C, fibres from the arci- 

 form plexus penetrating the fold of the olivary lamina : B, bundles surrounding the folds of the 

 lamina and also penetrating them : D, fibres derived both from the transverse and internal arciform 

 fibres, forming as it were a stem to the olivary body, radiating subsequently within the lamina, with 

 the cells of which these fibres are intimately connected. 



Fig. 43. G-roup of cells from the postero-lateral portion of the auditory nucleus of the sheep, 

 magnified 120 diameters. The bundles represented in this figure are mostly derived from the cere- 

 bellum, with which this part of the nucleus is intimately connected. 



Plates XIII, XIV, XV, and Fig. 12^*, Plate XVI, are outlines representing the situations of the 

 principal cell nuclei, and a few other details of the photographs given in the preceding plates of which 

 they bear corresponding numbers. The lettering is the same in all the figures. 



a — border of external arciform fibres. j — longitudinal columns (Stilling's constant 



h — caput cornu posterioris. root of the fifth). 



c — central canal. k — border of longitudinal fibres, just above 



d — cervix cornu. which the posterior division of the auditory root 



e — little cell group thrust out from the hypo- appears. 



glossal nucleus. I — longitudinal fasciculi passing through the 



/ — cells in the anterior spur of the vagus vagal and accessory nuclei, 



nucleus. m — posterior longitudinal fasciculi. 



g — cells in the posterior spur of the vagus v — accessory olivary nucleus (Stilling), 



nucleus. ^5 — post-pyramidal body. 



/i^anterior cornu. r — restiform body. 



i — small pyramidal nuclei. p, p — post-pyramidal nucleus. 



