12 H. BERKELBACH VAN DER SPRENKEL 
anterior secondary gustatory tract (fig. 8), already so conspicu- 
ous in Tinea, is thus completed in Silurus. This, however, 
should not astonish us, since also in the position of the motor 
V nucleus (fig. 6) the predominating influence of this gustatory 
system and its direct surroundings on the position of the motor 
cells is so strikingly exhibited. 
In Silurus the descending branch of the motor VII is split up 
into two parts by dorsal arcuate fibers (see fig. 4) and a comparison 
with the Pleuronectidae and other bony fishes reveals that that 
part of the descending branch of the VII which descends behind 
the dorsal commissure contains the fibers which in other teleosts | 
proceed to the dorsal column of the motor X nucleus. 
The frontal part of the VII nucleus contains, just as in Tinea, 
some more dorsally located cells (fig. 2). The greater part of the 
motor VII nucleus lies, however, in the line continuing the V 
nucleus (fig. 8), forming one interrupted column with it, both 
influenced in their position by the anterior secondary gustatory 
tract and spinal V tract. This forms a great contrast with the 
‘position found in Mormyrus, where the facial nucleus—on ac- 
count of the slight development of the anterior gustatory tract— 
has kept its more primitive dorsal position near the floor, of the 
fourth ventricle (fig. 21). 
The sensory VII root is a predominating feature in the structure 
of the oblongata of this fish. The hypertrophy of this root, as 
already stated above, is chiefly due to the enormous development 
of its recurrent branch, which supplies the. taste organs of the 
head and of the whole body with sensory fibers.!° The large 
size of this root, and especially of its ramus recurrens, has al- 
ready been observed by Stannius (loc. cit., p. 51). In figure 1 
I give a photograph of its anatomical relations from a preparation 
made by Mr. Schepman. 
As I have already said, Herrick has stated the same for North 
American siluroid fishes (Jour. Comp. Neur., vol. 15, 1905, p. 
378). The taste buds on the skin of Silurus, as previously 
10 Regarding the older and erroneous views about the ramus recurrens VII, 
see M. Juge, Recherches sur les nerfs cérébraux et la musculature céphalique du 
Silurus glanis L. Revue suisse de zoologie, T. 6, fase. 1, Geneva, 1899, p. 91. 
