Motor System 47 



sympathetic ganglia. Those of the X and XI nerves arise 

 in a single column of cells which has a dorsal situation near 

 the floor of the fourth ventricle (Pis. VI.-VHI.). This nucleus 

 — the dorsal motor vagus nucleus {nucleus motorius dorsalis X) 

 — ends anteriorly a short distance In front of the rostral 

 extremity of the nucleus XII, where it is separated from 

 the fourth ventricle by the large nucleus of Staderini and the 

 chief vestibular nucleus and lies just medial to the corre- 

 sponding sensory centre (nucleus fasciculi solitarii). Passing 

 backwards, the nucleus of Staderini rapidly decreases until 

 the vagus nucleus, which grows somewhat larger, comes to lie 

 lateral to It and immediately under the floor of the ventricle. 

 From here, It can be traced dow^n into the closed part of the 

 oblongata, where it ends near the posterior extremity of the 

 hypoglossal nucleus. 



The general visceral components of the facial and the 

 glossopharyngeal nerves are connected with the salivary 

 glands, and their nuclei are the superior and the inferior 

 salivatory nuclei respectively. These are small groups of 

 scattered cells. They are practically continuous with each 

 other and occupy a more lateral and deeper position than the 

 dorsal motor X nucleus, a short distance in front of Its anterior 

 extremity. 



The special visceral efferent cells, on the other hand, 

 which send fibres Into nerves V, \TI, IX, X, and XI, have 

 undergone a marked change In position In a ventral and 

 somewhat lateral direction, a change which has gone farthest 

 In the case of the motor facial nucleus {nucleus motorius VII). 

 This large group of cells Is to be found close to the ventral 

 surface of the brain, midway between the spinal V root and 

 the pyramid, and some distance behind the level where Its 

 root emerges (PI. IX.). It is composed of several separate 

 cell-masses, which Papez has found in both rat and cat to 

 give rise to the fibres of distinct branches of the nerve. The 

 root fibres do not run directly to the point of emergence, but 



