36 H. BERKELBACH VAN DER SPRENKEL 
The entrance and courses of the lateral nerves are as follows: 
The nervus lateralis anterior, vestibularis and facialis form one 
complex (figs. 15, 16, 17), of which the lateralis anterior is the 
largest component and enters the bulb farthest frontally (fig. 20). 
Its fibers run as a very large bundle in a dorso-medial direction 
to end in the dorsal unpaired gray substance that is covered by 
the crista cerebellaris [fig. 15, fig. 20 (1)]. 
The root passes between a coarse fibered tract, lying laterally, 
the tractus spino-cerebellaris, and a region of gray matter which 
separates it from the spinal V tract (fig. 15, n.VI/Il.). This 
gray matter contains the nucleus mentioned above (see p. 28) 
which consists of rather large cells. The frontal pole of this 
nucleus lies more dorsally than its caudal pole and frontally the 
nucleus is continuous with the gray substance of the nervus 
lateralis and medially with that of the vestibularis (fig. 15, n.VI//). 
Whether this nucleus is the homologue of the nucleus ventralis 
VIII in other fishes (nucleus tangentialis of Cajal and Tello) 
cannot be stated with certainty, but this is most probable. 
Not all the fibers of the nervus lateralis anterior end in the 
unpaired dorsal gray. It appears that a considerable part 
[fig. 20 (2)] of the fibers run backward forming a descending tract, 
just as in Silurus. Whether this tract is formed by bifurcation 
of the entering root fibers I cannot say, but it seems quite pos- 
sible. The descending tract continues caudad for several sec- 
tions in the same region of the bulb in which it first appears, then 
it shifts more laterally and proceeds in a dorsal direction laterally 
from the spino-cerebellar tract (fig. 16). It then forms a part of 
the substance which Franz? has called lobus facialis, but which 
really is the lobus lineae lateralis. It is provided with granular 
cells and covered by a crista cerebellaris which is separated from 
its white substance by a double row of large cells. 
The nervus lateralis anterior is the most lateral component 
in the complex of root fibers at the level of entrance. The dis- 
tinction between it and the nervus vestibularis is not, however, 
always easy to make. Then, some sections more caudad, after 
39 Zool. Jahrb., Bd. 32, Tafel 26, fig. 6. 
