979 
dorsal region thus reaching the sensory centra which control the 
taste. Where this tendency is not evinced, or but slightly, the 
XII nucleus has comparatively kept its original connection, and 
is still wholly or partially connected with the motor cervical grey 
matter of which it is.the direct continuation. For this reason it lies 
in such animals more spinally and more ventrally than in animals 
with a finer sense of taste where, in obedience to neurobiotactic 
influences, it has had to separate from the cervical grey matter in 
order to shift in a fronto-dorsal direction. The connection of the 
frontal remnant of the cervical grey matter with the nucleus motorius 
dorsalis X, which in Phocaena occurs throughout a small extent 
but nevertheless very distinctly, is likewise a primitive phenomenon 
which has been described by Karpers in the Alligator and in Birds, 
and I have observed it to a slight degree and in a more caudal 
region in the giraffe. 
After the extremely strong development of the oliva inferior, its 
late appearance, not until near the calamus in the porpoise, is 
remarkable. 
CONCLUSIONS. 
1. In Phocaena the dorsal motor vagus nucleus spreads out only 
through a small portion, not more than */,, spinally from the calamus. 
In this portion the nucleus is poorly developed, at first it does not 
even occur constantly. In the same region an equally poorly developed 
commissural vagus nucleus occurs. As far as the immediate vicinity 
of the calamus its direct connection with nucleus XI can be repeatedly 
demonstrated. At the time of its greatest development it is club-shaped, 
the broadened portion is directed medially; the tail running under 
the ependyma may even nearly reach the side wall of the oblongata. 
This tail, frequently loosely built, often breaks up into different cell 
groups. The cells, to a maximum number in each section of 100, 
are of two types and different in size. 
2. Of the nucleus ambiguus not a trace is to be seen spinally 
from the calamus, though in sections spinally and frontally from 
the calamus before its appearance distinct radiations can be seen 
from the dorsal motor vagus nucleus in a ventro-lateral direction, 
which in my opinion confirms Karpers’ theory that in mammals at 
least the ambiguus is a splitting of the dorsal motor vagus nucleus. 
The frontal extremity of the ambiguus in Phocaena is very large, 
and begins at the frontal pole of the tongue nucleus; it passes directly 
over into the nucleus facialis. 
