THE LATERAL CANAL SYSTEM. Soli 
fusiform, though still to some extent translucent. Immediately on passing 
from the fusiform into these masses the nervules dissect into a multitude of 
very fine branchlets, so fine and so numerous indeed that the masses, on 
Leucicorus and Mixonus, appear to be quite filled with them. Different 
genera exhibit few or none of the nervules outside of the fusiform or even, 
in many, outside of the centrum. Immediately on passing from the fusiform 
mass into the outer masses, in the genera just mentioned, the nervules divide 
into finer threads, but on nearing the opposite edges they again unite to 
form larger branches some of which pass inward to meet nerves going to the 
brain and others of which accompany the minute connecting thread to enter 
similar masses in the next organs. Toward the left hand end of fig. 2 
of Plate XXXIX. below the pectoral fin of fig. 1 of the same plate, an 
attempt is made to depict both the inner nerve, supplying the branches for 
the centrum, and the outer, gathering up some of the nervules and complet- 
ing the circuit. Between the two disks drawn in this figure the branchlets 
have not joined into a single nerve, but they traverse the distance as dis- 
tinct nervules which branch again on reaching the next organ. As may be 
seen from this figure there is much difference in the conditions of the nerves 
between the organs of various directly connected pairs; sometimes the ner- 
vules are numerous, but in the nearest interspace again they may be very 
few. 
' Generally the cephalic organs of the lateral system receive their nerves 
fom the trigeminal and the facial groups, and to a less extent from the 
glossopharyngeal, and those of the body depend upon the vagus. Within 
certain limits the main features of the innervation are similar in the differ- 
ent families noted below, but beyond these limits among the details there 
are considerable divergences. This is shown by comparison of the nerves 
of individuals of the same species, Lassozelus nasus, in figs. 1 and 3 of Plate 
LXXVIUI. On figs. 1 and 2 of this plate the nerve has been traced back 
from each disk to the brain. These figures give an approximate idea of the 
condition, in all of the main features, in all of the teleosts here dwelt with. 
By comparison with Ava calva it will be seen that there is a rather close 
correspondence in the principal features of the innervation. A feature of 
special interest in a contrast with these figures is the fact that Amia exhibits 
an arrangement of the system that in respect to aural and supraorbital 
branches of the cranial canal is intermediate between that of the Scorpenoid, 
or the Cottoid, of Plate LXXI. fig. 1, or figs. 2 and 3, on which the aural 
