438 ZOOLOGY. 
superior (Os) and inferior (Ot), arise from the front of th« 
orbit near the interorbital septum. The disposition of th« 
wt 
a 397.—Anatomy of the brain of the Cunner, dorsal and side view. 3B, Ol, olfac- 
tory lobes ; the crura and the thalami not represented.—Drawn by C. S. Minot. 
recti is very constant, but the obliqui vary considerably in 
their origin in different Vertebrates. 
If a perch be cut through transversely, so that the section 
passes through the fore-part of the 
air-bladder, and the anterior portion 
then looked at from behind, a very 
instructive view will be obtained, as 
in Fig. 398. The best sections can be 
made by first freezing the fish. The 
vertebral column (V) appears a little 
above the middle; overlying it is the 
neural canal with the spinal cord ; im- 
mediately below it is the descending or 
dorsal aorta (Ao), on either side of 
which follow the kidneys (’), resting 
directly upon the air-bladder (B/). 
Lowermost is the body-cavity, with 
the stomach (), and intestine (Zn),  2is,393,7 Transverse section 
surrounded by the liver, which has 9f,2,Cunner—Drawn by 0.8 
been almost entirely removed. The 
rest of the section is occupied by muscles, which, it will thu 
be szen, make up the main bulk of the body. (Minot.) 
