678 



OF THE FUNCTIONS OF THE NERVOUS SYSTEM. 



mer divides, while passing through the Pons Varolii, into two bands, one of 

 which proceeds upwards and forwards as a part of the "motor tract" (m t) of 

 the Crus Cerebri, whilst the other (o) proceeds upwards and backwards to reach 

 the Corpora Quadrigemina (c, D). The olivary columns are continuous in- 

 feriorly with the anterior columns of the Spinal Cord; and afford attachments 

 to the anterior roots of the 1st and 2d cervical nerves. The vesicular nucleus, 

 which is known as the corpus dentatum, seems to be especially connected with 

 the origins of the nerves concerned in the regulation of the movements of the 

 tongue; thus we find that anteriorly a portion of the roots of the Hypoglossal, 

 which is the motor nerve of the tongue, issue from it; whilst posteriorly a por- 

 tion of the roots of the Grlosso-pharyngeal, which is one of the sensory nerves 

 of that organ, seem to terminate in it. m. The Restiform bodies, in like 

 manner, each consist of fibrous strands (F) inclosing a gray nucleus. The 



Fig. 179. 



Transverse section of the medulla oblongata through the lower third of the olivary hodiee. (From Stilling.) 

 Magnified 4 diameters. 



a. Anterior fissure, b. Fissure of the calamus scriptorius. c. Raphe. d. Anterior columns, e. Lateral 

 columns, f. Posterior columns, g. Nucleus of the hypoglossal nerve, containing large vesicles, h. Nu- 

 cleus of the vagus nerve, i, t. Gelatinous substance, k, fc. Roots of the vagus nerve. I. Roots of the 

 hypoglossal, or ninth nerve, m. A thick bundle of white longitudinal fibres connected with the root of the 

 vagus. . Soft column (Zartstrang, Stilling), o. Wedge-like column (Keelstrang, Stilling), p. Transverse 

 and arciform fibres, q. Nucleus of the olivary bodies, r. The largo nucleus of the pyramid, s, s, s. The 

 small nuclei of the pyramid, u. A mass of gray substance near the nucleus of the olives (Oliven-N(t>erikerri) 

 u, q, r, are traversed by numerous fibres passing in a transverse semicircular direction, v, w. Arciform 

 fibres, x. Gray fibres. 



fibrous strands pass upwards into the Crura Cerebelli; whilst below they are 

 chiefly continuous with the posterior columns of the Spinal Cord, having also 

 some connection with the posterior part of the middle columns. These Cere- 

 bellar columns also communicate, however, with the anterior columns of the 



