132 The Alligator and Its Allies 
BRAIN 
The cervical cord passes insensibly into the 
medulla, the dorsal furrow becoming wider and 
more shallow as it merges into the fourth ventricle. 
A dorsal view of the brain is shown in Figure 30, 
A. The most prominent structures here seen are 
the cerebral hemispheres, VH, whose combined 
transverse diameter is greater than their longi- 
tudinal. The tapering, cephalic end of each hemi- 
sphere forms an olfactory tract, I, which extends 
cephalad to form the olfactory bulb, B. ol. Lying 
between the caudal ends of the hemispheres is a 
small conical body, G.p., called by Bronn and 
others the pineal body. The writer has found (62), 
however, that this body is the paraphysis rather 
than the epiphysis. Caudad to the cerebra- 
hemispheres and in contact with them are the 
optic lobes, MH; they have about the same 
shape and position as in the frog, but are much 
smaller in proportion to the size of the hemispheres. 
Immediately caudad to the optic lobes is the cere- 
bellum, HH, somewhat elliptical in outline as seen 
from above. 
Extending caudad from beneath the cere’ ellum 
is the medulla, NH, with its triangular fourth 
ventricle. The outlines of the medulla are some- 
what obscured by the numerous roots of the 
eighth to eleventh cranial nerves, VIII-XI, which 
arise along its dorsal border. The medulla, as was 
