220 FREDERICK TILNEY 
ELEMENTS IN THE DIENCEPHALIC FLOOR OF THE ADULT CAT 
The lateral view of a model reconstructed to show the left 
side of the floor of the interbrain in an adult cat is reproduced 
in figure 2. At its cephalic extremity is the optic chiasm (4), 
while its most caudal structure is the mammillary body (27). 
41 
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Fig. 2 Lateral view of forebrain reconstruction in adult cat. X 35. The 
unshaded area shows the cut surfaces of the reconstruction. 4, chiasm; //, 
infundibular stem; 13, infundibular process; 27, mammillary body; 32, post- 
chiasmatic eminence; 34, post-infundibular eminence; 41, supra-optic crest; 
42, supra-optic recess. 
Above the optic chiasm and extending from the median line in 
either direction along the dorso-cephalic border of the chiasm 
and optic nerve is a ridge-like elevation, the supraoptic crest (41). 
This ridge is most prominent at and near the median line. It 
is most conspicuous in the carnivores, especially in the Felidae, 
but it is present in all the forms examined. The chiasm (4) 
