CRANIAL NERVES OF SILURUS AND MORMYRUS 13 
described by Merkel (loc. cit., supra, p. 74), can be seen with the 
naked eye, by reason of their surrounding pigment, over the whole 
body and even the tail. 
Near the periphery of the oblongata the sensory VII lies later- 
ally of the sensory V (fig. 5), and is easily distinguished from it 
by the finer caliber of its fibers. This big root gradually shifts 
into the bulb. Running in a medial direction over the descend- 
ing V (fig. 6), it is separated from the latter by some very coarse 
fibers of the nervus vestibularis (fig. 7). It can be easily observed 
how the sensory VII is pushed aside on its way to the lobus 
sensibilis VII by the enormous development of the lobus lineae 
lateralis (Johnston) (fig. 7). More caudally the lobus lineae 
lateralis is pushed dorsad and laterad, where the sensory VII 
enters the big lobus sensibilis VII (fig. 8). 
The mode of termination of the sensory VII root in the lobus 
sensibilis VII is repeated in the case of the sensory IX and X 
nerves, so that I wish to describe it in a little more detail. 
As soon as the sensory VII has reached the lobus sensibilis VII, 
it sends a considerable part of its fibers to form a dorso-lateral 
capsule of the lobe. The capsular, or peripheral, fibers are of 
especial importance to us, because, as Herrick has first observed, 
their number is increased in those fishes which possess a larger 
number of taste buds (consequently they are further enormously 
increased in the sensory X nucleus.of cyprinoid fishes where the 
palatal organ has so many taste buds). 
Besides this capsular root, the sensory facialis has two other 
roots, of which one pierces into the center of the lobus (fig. 8, 
centr.f. VII) and the second proceeds in a medial direction be- 
neath it, crossing the fibers of the secondary gustatory tract, 
then running some distance backward near the lateral wall of 
the fourth ventricle. These fibers, as well as a part of the central 
fibers of the sensory VII, descend a considerable distance (fig. 9, 
m. VII. f.), so that the prevagal part of the fasciculus solitarius 
is well developed in Silurus and does not disappear until the level 
of entrance of the IX nerve. 
Since, apart from the capsular taste fibers, the facialis contains 
also general tactile fibers for the mucous lining of the mouth, 
