384 Animal Life 
Then the‘ laborious task of catching, killing and 
swallowing did not have to be repeated so often 
to get enough food for a meal. Tbe more he ate 
the faster he grew; the bigger he got the more 
he was able to kill at one time. It soon became 
no effort to eat a rat. Then it became less trouble 
to eat a guinea-pig than two rats. 
These constricting snakes are so coloured that 
they melt into their surroundings. The boa-con- 
strictor, with his arrangement of yellowish-brown 
tints growing in depth and strength towards his tail 
till the bars across his back shade off into patches 
of chestnut-red with black edges, is almost invisible 
upon the moss-covered branch of a tree with the 
shadow of the leaves falling on his skin. He is 
most at home when climbing, and chooses a tree 
near water for his ambush. He selects his victim 
from the animals which come to drink, and catches 
it by the nose when it raises its head after drinking. 
a The animal is probably dead before it can realise 
oll ‘% : that it has been caught; for with a powerful twist 
IPRIPILONRIING) "HISHDS ITUIRINTANOIRI. of its neck the snake rolls it over and over, so that 
its body is wound round with the coils. Death is due to the sudden compression 
of all the internal organs, especially the heart and lungs; the bones are not 
necessarily broken. Then comes the most painful part of the business. The snake 
has to swallow its prey whole, as its sharp-pointed teeth are not capable of dividing 
it. The boa has to keep advancing its upper and lower jaws alternately over the 
dead animal’s body until it has been crammed down its throat. It is no wonder 
that these constricting snakes grow large in order that they may be able to eat 
large prey at long intervals. These great exertions are not to be lightly entered 
upon. The South American boa, from which these photographs were taken, only 
reaches the length of twelve feet, but some of the pythons grow over twenty feet 
long and can devour creatures as large as sheep and pigs, and can then go for 
months without food. 
When not eating, these snakes are lethargic. My boa, who knows that his food 
comes to him, would le coiled up without moving from meal to meal if I did not 
frequently take him out of his cage. Then he is interested in exploring the chairs, 
book-shelves, in fact everything that is climbable. In this way I keep him exercised. 
He is quite tame, and has only once resented being touched. Fortunately, however, 
these snakes are not really dangerous. When angry they bite. Them terrible crushing- 
power is only used against animals which they mean to eat. My boa is extremely 
humane. If he is not hungry he will crawl round and round his cage to get away 
from a guinea-pig that tries to nibble his scales. I have never known him bite 
any animal he did not mean to eat except myself, and that was when he was 
changing his skin, during which process all snakes are inclined to be irritable. Some 
of the pythons, however, are less forbearing, and seem to kill small animals from 
pure destructiveness and then leave them. Yet in a state of nature they are probably 
the most merciful of the carnivorous creatures. They say the soldier never sees the 
bullet which kills him. The victims of these snakes likewise never know the manner of 
their death. 
