130 MR. R. OWEN ON THE ANATOMY OF THE CHEETAH. 
In the domestic Cat, in Felis planiceps, Vig. and Horsf., and in Felis Caracal, Schreb., 
the os hyoides is connected to the cranium, as in the Genet and the Dog, by an unin- 
terrupted chain of bones: this structure, indeed, has afforded Professor Geoffroy one of 
his illustrations of the essential composition of an os hyoides. The same structure 
obtains in the Cheetah. From the difference in the voice, the feline animals might have 
been expected, a priori, to present some differences in that part of their anatomy which 
relates to it. 
A vertical elliptic pupil (which is so well calculated to exclude a too strong light 
from a retina adapted to crepuscular vision, and at the same time to admit of a rapid 
and sufficient expansion for the exercise of sight in the gloom of the evening,) is that 
form which is met with in all the smaller and weaker species of the feline genus: but 
in the more powerful and bolder species, which dare to attack a larger prey in the face 
of day, the pupil is of a circular form. The Cheetah agrees in this respect with the 
Lion, the Tiger, the Leopard, and the Jaguar ; and, from its natural docility and habits, 
may be regarded as the most strictly diurnal of the whole genus. 
The soft parts of living prey forming the food of the whole tribe, a consequent corre- 
spondence prevails in the structure of the digestive organs. The esophagus is remark- 
able for its width and its loose mode of connexion in the chest, both of which facilitate 
the passage of the coarsely divided flesh. The lower half of this tube is characterized 
by transverse rug@ ; and the muscular fibres, which are at first disposed spirally,—the 
two layers in opposite directions,—assume at this part a disposition analogous to that 
in the human subject, the outer layer being longitudinal, the inner one transverse. 
I have also discovered at this part of the wsophagus a third layer of muscular fibres, 
which is longitudinal, and more internal than the transverse: this layer does not extend 
beyond that part of the esophagus in which the transverse rug of the lining membrane 
exist ; and as it adheres closely to the membrane, I am inclined to believe that it pro- 
duces the rugous disposition peculiar to that part: a preparation demonstrating this 
muscular layer in the Lion, is in the Museum of the College of Surgeons. A similar 
structure exists in the Cheetah. 
The esophagus is not prolonged into the abdomen in any of the feline tribe, but ter- 
minates at once in the stomach. This viscus, compared with the human stomach, pre- 
sents a less extent of the left blind extremity, or saccus cecus of Haller; the pyloric 
half is more tubular, and is more abruptly bent upon the cardiac; the lining mem- 
brane presents fewer rug@; and the disposition of these, when the stomach is con- 
tracted, is more regularly in the longitudinal direction. But the most marked cha- 
racteristic of the feline stomach is the mode in which the lesser omentum is continued 
upon it: this duplicature is not attached in a regular line to the lesser curvature, but 
extends in a scolloped form upon the anterior surface, upon which the branches of the 
coronary artery are further continued before penetrating the muscular coat. The Cheetah 
