1132 
vagus,” genuine vagus fibres run, but there is no doubt whatever 
that a part of the nervus accessorius originates in the oblongata. 
Even the fact that fibres originate in the dorsal motor vagus nucl. 
does not in my opinion prove that they are necessarily vagus fibres. 
I consider it remarkable that in all the animals | have examined as 
yet the dorsal motor vagus nucleus shortly after its caudal appear- 
ance exhibits in the lateral part a type of cell which is larger 
than its original cell-type, a type which is maintained over a part 
of the nucleus, chiefly at its ventro-lateral and ventral sides.’) I 
venture to express the supposition that these large cells, although 
they pass over into the dorsal motor vagus nucleus, are accessorius 
elements. The accessorius nucleus, which has originated ontogenetic- 
ally and phylogenetically from the caudal part of the dorsal motor X 
nucleus (Kappers’)), thus exhibits this relationship in Camelus and 
Lama still in the full-grown animal. | 
The enlargement of the dorsal motor vagus nucleus in Camelide 
with the motor commissural nucleus may be explained by the striking 
differences which the oesophagus and stomach of these animals 
exhibit from other ruminants. Not only is the oesophagus in these 
animals remarkably long in proportion (in Camelus + 2 meters !) 
but this organ is likewise in every respect particularly rich in glands 
(Lessee), and, as has already been stated, the rumen contains many 
glands in some of its divisions. In this connection | may mention 
that, after I had shown the motor commissural vagus nucleus in 
Camelus and Lama, I car efully examined my series of the sheep and the 
the goat in respect to this, and only found in some sections indications 
of this connecting nucleus, a remarkable symptom, since in these 
animals glands are but rarely met with in the oesophagus and in 
a part of the omasus. The position of the nucleus motorius com- 
missuralis vagi in the eommissura inferior visceralis which contains 
descending sensory fibres of oesophagus and stomach must be ascribed 
to neuro-biotactic influences. 
The short course of the nervus laryngeus inferior seems to 
be correlated with a smaller development of the caudal third 
part of the nucleus ambiguus. The pronounced development of 
the frontal enlargement of the nucleus ambiguus, the centre of 
the motor glossopharyngeus, may be explained by the exceptional 
1) SruurmAN has also pointed out the occurrence of two celllypes in the dorsal 
motor vagus nucleus. F. J. Stuurman, “Over den oorsprong van den nervus vagus 
by het konijn.” Acad. Proefschrift, Amsterdam. 1913 
2) Weitere Mitteilungen über Neurobiotaxis, VII. Folia Neurobiologica. Bnd. VL. 
Sommerergänzungs Heft, p. 94. 
