36 THE SNAKES OF SOUTH: AFRICA. 
contraction of the muscles of the head. Slowly, but surely, the 
prey is seen to vanish from sight. When the hindquarters have 
disappeared into the throat of the snake, the task is easy. The 
muscles of the body set up a series of contractions which force 
the creature down the gullet into the stomach tube. When it 
gets to the middle part of the snake where the real stomach is 
situated, the victim’s body goes no further, until digested or 
disgorged. Sometimes a snake will seize a large rat, toad, or 
frog and begin by swallowing one of the hind legs. Finding that 
eventually he cannot make much progress, he rejects the swallowed 
leg and moves round to the head and begins again. 
Fic. 17.—A Puff Adder swallowing a large Barn Rat. Note how the snake makes use of 
his fangs to help to get the body of his victim into his mouth, 
I have seen a Puff Adder in captivity swallow three rats in 
succession. So powerful were its digestive juices that it com- 
pletely digested them all. Boomslangs will, at times, swallow 
seven to a dozen frogs in rapid succession. When the prey 
is of small bulk, it is quickly swallowed. A Puff Adder takes 
from half an hour to a full hour, and sometimes longer, to swallow 
a large rat. 
POWER OF DISGORGING PREY. 
It is popularly supposed that snakes cannot release their 
prey once it is well within their jaws, owing to the nature of their 
teeth, which are curved backwards. On the contrary, when 
alarmed or irritated, a snake invariably disgorges its prey, either 
