134 The Alligator and Its Allies 
caudad to the acoustic and extending along the 
upper border of the medulla and beginning of the 
spinal cord, are seen a dozen or more small nerve 
roots, which unite to form the glossopharyngeal, IX, 
vagus, X, and spinal accessory, XI, nerves. Ven- 
tral to the roots of the last, on the ventral surface 
of the medulla, arise the roots of the hypoglossal 
nerve, XII. A short distance caudad to this nerve 
are seen the first two spinal nerves, 1 and 2, which 
have, as noted above, no dorsal roots. 
A ventral view of the brain is shown in Figure 30, 
B. The cerebral hemispheres, VH, have the same 
outline, of course, as in the dorsal view, but the 
rounded projection from the caudal end of each 
is here seen on each side of the infundibulum, Inf. 
The infundibulum is in close contact with the 
chiasma anteriorly, and lies close between the 
converging optic tracts, Tr. opt. From the chi- 
asma the optic nerves, II, extend, in an antero- 
lateral direction, almost at right angles to each 
other. The appearance of the olfactory tracts, I, 
is the same as in the dorsal view. Caudad to the 
infundibulum, from the cerebral peduncles, ZH, 
arise the rather small oculomotor nerves, III. 
Caudad to these, from near the ventral fissure, 
on the middle region of the medulla, arise the ab- 
ducens nerves, VI, and from the ventral side of the 
posterior part of the medulla and of the anterior 
end of the cord arise the hypoglossal, XII, and 
the first two spinal nerves, 1 and 2. The ori- 
