589 



appearance of Purkinje cell dendrites (Figs. 5, 7, and 8), Deeper in 

 the body of the acusticum are large cells whose dendrites do not 

 reach the cerebellar crest and do not present the peculiarities of 

 Purkinje cell dendrites. Between these two varieties of cells are 

 found transitional forms of every possible degree, so that we are 

 obliged to call all a single type of cell. The neurites of these cells 

 run to the base of the medulla, and part of them may reach the 

 opposite side. 



3) Center for the VII-IX-X nerve group. This center is the 

 Lobus vagi of Goronowitsch, and includes the equivalent of the 

 L. trigemini of Mayser. At the posterior end of the medulla there 

 appear mesial to the nucleus of the spinal Vlllth. and close to the 

 dorsal raphe, a few cells, some of which send their neurites through 

 the dorsal horn ventral to the Nucleus funiculi to the lateral portion 

 of the medulla (Figs. 1 and 2). Immediately behind the calamus 

 scriptorius the lobes of the two sides are connected by the Commissura 

 infima Halleri (Fig. 2). The fibres constituting this commissure come 

 from cells situated in the L. vagi either at the level of the commissure 

 or further anteriorly. The size and position of the L. vagi are shown 

 in Figs. 1 — 7, Its structure is simple. The several dorsal roots of 

 the Xth. and IXth. nerves enter at intervals and break up in the 

 dorsal part of the lobe, as shown in Figs. 4 and 5. The fibres usually 

 show Y-branching. The fibres end in relation with cells of the II 

 type, whose neurites break up mostly in the ventral and lateral parts 

 of the lobe. This part of the lobe is chiefly made up of cells whose 

 neurites take a ventro-lateral course to the lateral part of the medulla 

 (Figs. 2 — 6). Here, the fibres either pass anteriorly or posteriorly 

 without dividing, or they divide, one branch going anteriorly, the 

 other posteriorly. The smaller number of fibres turn posteriorly. 

 They form a distinct bundle of non-meduUated fibres ventral to the 

 spinal Vth. and continue into the cord. The anteriorly directed bundle 

 runs ventral to the acusticum to the anterior end of the medulla, 

 where it ends in a large nucleus forming the antero-lateral limit of 

 the medulla, lateral to the median Vth. nucleus (Fig. 10). This is 

 the Rindenknoten of Mayser and Goronowitsch. Connecting these 

 secondary vagus nuclei of the opposite sides are two commissural 

 bundles of non-medullated fibres which come, at least in part, from 

 the cells of the nuclei. These commissures pass through the cerebellum 

 and the fibres give off a considerable number of collaterals into the 

 granular layer (Figs. 10 and 11). 



The description just given applies in general to the vagus lobe, 



