140 
vagi* (r. lat. prof. #.), coursing below the above, and 
between the dorsal and lateral musculature, far from the 
surface. The latter gives off no branches until it passes 
upwards and outwards to supply the sense organs of the 
posterior half of the main portion of the lateral canal. [ft 
is at intervals very closely connected with branches from 
spinal nerves, but no fibres are exchanged as far as we 
could see. ‘The superficialis division, besides supplying 
its portion of the lateral canal, gives off in front and above, 
in fact as its first branch, the R. lateralis recurrens vagi 
(1. ree. w.). This is also a true lateral line nerve distri- 
buted to pit organs, and must therefore not be confounded 
with the R. lateralis accessorius (trigemini), although in 
some fishes its homologue appears to accompany the latter. 
Its course, which is very extensive and just under the skin, 
is shown in the chart, and it corresponds precisely to the 
similar branch arising from the facial, and called the R. 
lateralis recurrens facialis (/. rec. viz.). 
Nervus Vagus—xX. 
Arises by a single large root, which is, however, 
formed by several large bundles (Stannius says 5) uniting 
just on the surface of the medulla, and which is further 
reinforced by two very small bundles in front, as shown 
in the chart. This root (7. #.) is quite distinct both from 
the roots of the glossopharyngeus and lateralis,t and in 
fact the roots of these three nerves are more distinct and 
clear in the Plaice than in most Teleosts. The vagus root 
* These nerves must not be confused with the R. lateralis trigemini of 
the Cod (cp. Parker’s ‘‘ Zootomy’’), which is not represented in the Plaice 
at all. The latter is a communis nerve supplying its own, and not 
lateral, sense organs. It has no connection typically with the trigeminal 
nerve, and should be called the R. lateralis accessorius. 
+ Stannius states that fibres pass from this root to the root of the 
lateralis in the Plaice, but this is not the case, 
