HeErrIcK, Nerves of Silurotd Fishes. , 213 
dorsal line. Small pit organs are, however, more uniformly, 
though sparsely, distributed over the whole body surface, in- 
cluding the base of the dorsal fin. 
The ventral branch of the lateral line nerve (Fig. 1, v. daz. 
X ) turns at once laterally and ventrally, anastomosing with the 
ventral ramus of a spinal nerve, passing close to the lateral line 
canal and supplying its fifth organ. This is the only organ of 
the lateral line canal supplied by this nerve. Other fibers supply 
a dense cluster of small pit organs about the base of the pectora] 
fin, The branch then runs back close under the skin laterally 
of the ventral musculature and supplies small pit organs of the 
skin ventrally of the lateral line canal as far back as my sec- 
tions run, or nearly to the pelvic fins. This branch corresponds 
to the superficial branch of the lateral nerve of Jucs’s descrip- 
tion of Silurus (’99, p. 131). 
IV. THE SYMPATHETIC NERVOUS SYSTEM. 
The sympathetic system has not been carefully studied and 
I can add but little to the brief note given by Wricut (84a, 
Pp. 372), asits fibers have very poorly developed medullary 
sheaths or none at all and my methods are not well adapted for 
them. The system as a whole, as in Gadus, deviates far from 
the peculiarly complex arrangement which is typical for teleosts, 
though it may evidently be derived from that arrangement. 
The sympathetic ganglionated chain of the trunk runs 
close to the centra of the vertebrae and so far as examined (viz. 
in the most cephalic spinal segments) contains ganglion cells 
quite uniformly scattered through it. Under the caudal end of 
the basi-occipital the ganglion cells disappear, to be followed 
farther cephalad bya large ganglion. The chain meanwhile 
approaches the median line and at the level of the vagus fora- 
men meets the chain of the opposite side in a large unpaired 
ganglion. This ganglion bifurcates cephalad and the chains of 
the two sides rapidly separate, becoming non-ganglionated, and 
continue cephalad, under the basi-occipital mesially of the X 
and IX ganglia and separated from them by a big vessel. The 
non-ganglionated sympathetic cord continues forward along the 
