52 COLUBRIDA. 
ment not only is great dilatability of the mouth obtained, 
which is also aided by a peculiarity in the structure of the 
joint, but one side of either jaw is capable of acting inde- 
pendently of the other; and as the animal is gradually 
taking its prey, one side of the jaws is extended forwards, 
and the two rows of teeth of the upper, and the single row 
of the lower, fixed into the integument ; then the opposite 
side of the jaws is stretched forwards in the same manner, 
and so on alternately, until the victim is thus gradually 
and often slowly conveyed into the esophagus, and by the 
muscular action of this part it is swallowed. When a frog 
is in the progress of being swallowed in this manner, as 
soon as the Snake’s jaws have reached the body, the other 
hinder leg becomes turned forwards; and as the body 
gradually disappears, the three legs and the head are seen 
standing forwards out of the Snake’s mouth in a very sin- 
gular manner. Should the Snake, however, have taken 
the Frog by the middle of the body, it invariably turns it 
by several movements of the jaws, until the head is directed 
towards the throat of the Snake, and it is then swallowed 
head foremost. This process will remind all who have 
witnessed the curious sight of the great Boa taking its food, 
of the manner in which that enormous reptile effects its de- 
glutition, after it has, by the pressure of its mighty sides, 
killed and crushed the bones of its victim. 
The scene above-described is one which I have often wit- 
nessed; and I once saw two Snakes seize upon the same 
hapless frog. As this circumstance is not unlikely to hap- 
pen in their native state, it may not be out of place to 
mention the result. On placing a frog in a large box, in 
which were several Snakes, one of the latter instantly 
seized it by one of the hinder legs, and immediately after- 
wards another of the Snakes took forcible possession of the 
