THE CENTRAL RELATIONS OF THE CRANIAL NERVES 
IN SILURUS GLANIS AND MORMYRUS CASCHIVE 
H. BERKELBACH VAN DER SPRENKEL 
Assistant in the Anatomical Institute at Utrecht 
TWENTY-ONE FIGURES 
The following researches were started with the idea of study- 
ing the topography of the motor nuclei in the brain of Silurus 
glanis, since a description of these nuclei in the central nervous 
system of siluroid fishes has not yet been given and we may 
expect interesting relations in this connection on account of the 
enormous development of special sensory systems arid their 
secondary connections.! 
It is known that the siluroids*—including also the European 
representative of that order, Silurus glanis*—are distinguished 
by an extraordinary development of the sense of taste, the re- 
ceptive organs of which are distributed over the head and the 
body and are innervated by the ramus recurrens facialis, which 
is very large in these animals. This has been demonstrated, 
among others, by Herrick for Ameiurus melas, and our photo- 
graph (fig. 1A), taken from an anatomical preparation made by 
Mr. Schepman, shows the same for Silurus glanis. 
It was to be expected that the preéminence of one set of sen- 
sory impressions should have a pronounced influence on the 
structure of the central nervous system, which would also appear 
1 The olfactory and optic nerves are not discussed here because it was chiefly 
the medulla oblongata and basis mesencephali which interested me. 
2 C. J. Herrick, The central gustatory paths in the brains of bony fishes. Jour. 
Comp. Neur., vol. 15, 1905, p. 375. The organ and sense of taste in fishes. Bul. 
U. S. Fish Commission for 1902, pp. 237-272, Washington, 1904. The cranial 
nerves and cutaneous sense organs of the North American siluroid fishes. Jour. 
Comp. Neur., vol. 11, 1901, p. 177. 
3’ F. Merkel, Ueber die Endigungen der sensiblen Nerven in der Haut der Wir- 
belthiere. Rostock, 1880. 
