1129 
motor vagus nucleus, the XI nucleus did ‘seem to be constantly 
present and was very unequally developed. [n the very first sections, 
however, it could be seen; on an average it contains here 8— 20 cells. 
Concerning the nucleus ambiguus it may be said that in general 
this is better developed in the lama than in the camel. It begins 
caudally from the place where the nucleus XII is clearly present 
and where the anterior horns of the cervical cord are still visible. 
More frontally it soon enlarges, but soon decreases again, and occurs 
but very slightly in the calamus region. In the open part of the 
oblongata its appearance is very different; as far as the frontal pole 
of nucleus XII its ventro-lateral part is generally the most strongly 
developed; occasionally the nucleus then contains 20—25 cells. As 
far as the frontal pole of the dorsal motor vagus nucleus, the 
development is again very poor, after which we see a round group 
of 8—10 cells arise that enlarges greatly on a level frontal from the 
dorsal vagus nucleus. Originally two cell groups can be distinguished 
in the frontal enlargement, but very soon these join to form one 
large complex, containing at the most 75 cells, mostly of the large 
type; the majority of the large cells are here also found in the 
lateral part (fig. 13). Also this enlargement of the nucleus ambiguus 
distinctly lies in a more ventral plane than the rest of the nucleus; 
Frontal enlarge- 
ment of the nu- 
cleus ambiguus in 
the lama. Fig. 14. Auchenia lama !). 
(Explanation as in figure 6.) 
as is usually the case in lower mammals. It projects 56 sections 
in front of the frontal extremity of the dorsal motor vagus nucleus 
(fig. 14) and it is in this region that the first cells of the nucleus 
facialis appear. 
Also in the lama the connection of the nucleus hypoglosst with 
the anterior horn of the cervical cord be observed (fig. 14). Behind 
the calamus, the XII nucleus is poorly developed in this animal, 
and a division into groups can hardly be observed here. Frontally from 
the calamus the medial group appears, and soon after also the 
1) In this diagram (Fig. 14) the caudal extremity of the nucl. ambiguus is a 
little: shortened for clearness’ sake. 
