401 
organ. ‘This tendon enlarges into the belly of the muscle about 8 mm 
from its insertion on the eyeball (Fig. 13). 
The Nerves. 
The electric nerve leaves the brain between the optic lobe and 
the lobi inferiores. It runs craniolaterad for about 1 cm and then 
directly craniad, passing through a notch in the lateral angle of the 
opening in the cranial wall of the brain case, to enter the electric 
organ at about the middle of its caudal face. In the electric organ, 
as stated above, this nerve passes through a loop in the rectus superior 
and immediately divides into branchss which run in all directions to 
the electric tissue. A small branch which runs to the rectus superior 
is also given off at this point. It was impossible, however, with the 
material at hand to determine with absolute certainty exactly where 
this small branch is given off, and whether it does or does not connect 
with the- component of the third nerve described below. The fibers 
of the rectus superior which enclose the electric nerve are very loosly 
arranged at this point and very intimately associated with the nerve fibers. 
The rectus internus, rectus inferior and the obliquus inferior are 
innervated by a component of the third nerve which separates itself 
from the electric nerve a short distance before the latter enters the 
electric organ. This component lies lateral to.the electric nerve and 
accompanies it in-the substance of the electric organ for a distance 
of about 1 cm and then divides into branches to the above named 
muscles. The branch to the obliquus inferior pursues an almost 
straight course through the electric organ. 
The fourth nerve leaves the brain in the usual manner and runs 
craniad on the medial surface of the electric organ, ventral to the 
ramus ophthalmicus. Near the cranial end of the organ it curves 
laterad over the dorsal surface of the organ to its termination in the 
obliquus superior. 
The sixth nerve runs craniad in the usual manner and enters 
the rectus externus at the caudal surface of the electric organ. 
The optic nerves run forward from the base of the brain, side by 
side, and between the two electric organs, for a distance of about 
16 mm; they then diverge each curving laterad through the electric 
tissue in order to reach the eye. 
The olfactory nerve, on each side, runs craniad from the olfactory 
lobe, on the medial surface of the electric organ, directly dorsal to 
the optic nerve, and terminates cranial to the eye in the olfactory organ. 
A small nerve, given off either with or from the trigemino-facial 
Anat. Anz. XXIX. Aufsätze. 26 
