1128 
bottom of the ventricle; more frontally it loses this form because 
the ventro-lateral pole also enlarges, after which the structure of 
the nucleus becomes looser and the number of cells grows less. Here 
too, the ventro-lateral portion remains longest, and the dorsal motor 
vagus nucleus does not reach into the region of the nucleus facialis. 
The nucleus accessorii lies more medially into the lamat han in the 
camel, just on the border of the anterior and posterior horns. Near 
the spinal pole of the dorsal motor vagus nucleus it is well developed ; 
in some sections + 90 large XI cells, and medially from this, in 
the same level, 5—8 dorsal vagus cells can be counted (fig. 11). Very 
soon a tendency can be observed in the XI nucleus to extend medially ; 
in one section it contains as many as 35 large cells and it is clearly 
prolonged in the direction of the dorsal motor vagus-nucleus ; 
wr 
NN A BRL, 
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re eee \Ww 4 
SIG) a N 
Sk er NLS 
ey 5 Xf KP N 
YS. re : N \ 
Vide Loe BEA 
yer eee AA mG Fae See ee 
SIN ¢ . y, ee ten ae 
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ee. Er on A 
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iy Sas eee, a. 
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Fig. 11. A posterior horn, B anterior horn. _ Fig. 12. A posterior horn, B anterior horn, 
C canalis centralis. 
immediately after the two nuclei join to one large group containing 
55 cells, of which the most medial ones have kept the smaller type of 
the dorsal vagus cells, whereas the lateral cells exhibit the large acces- 
sorius-nucleus type (fig. 12 and 14). This constellation soon decreases 
in size and is only to be seen in 4 consecutive sections after which 
the vagus nucleus remains in its usual extent at that place; it con- 
tains then about 30 cells of mixed type; the large cell-type remains 
principally lateral. After this on more frontal levels with a very 
few exceptions nothing more of the nucleus accessorii is to be seen. 
Near the spinal extremity of nucleus XII, however, the process 
repeats itself to a slight extent, and we see a few XI cells rise and 
shift in a medial direction’). As far as the material at our disposal 
extended, i.e. 165 sections spinally from the beginning of the dorsal 
1) Not indicated in the diagram of fig. 14, 
