42 THE SNAKES OF SOUTH AFRICA. 
Boomslangs on the ground. Occasionally he has found them 
in shrubs, but their usual habit is to hunt for their prey, which 
consists mainly of lizards, lying on the ground. 
These chocolate Boomslangs are of the same species as the 
others. They vary only in colouration, induced by their altered 
habits. Green, or greenish-yellow, banded with black, being 
conspicuous upon the brown earth, dead leaves, and stones, wise 
Nature has adapted them to their surroundings by changing 
the colour of their skins. This adaptation of colouration of the 
various creatures to their surroundings is wonderful and 
mysterious. It is most certainly not induced by any thought- 
power, or desire in the snake’s brain. It is abundantly 
evident there is a protecting force or Law at work which 
operates without any conscious desire or wish on the part of 
the creatures whom it seeks to benefit, by making them as in- 
conspicuous as possible to their enemies and their intended prey. 
This great Natural Law is quite impartial, as are all the Laws of 
God. It makes the colour of one creature blend so perfectly 
with its surroundings as to enable it to steal upon its intended 
victim unawares, but it also seeks in a similar manner to render 
the intended prey as inconspicuous as possible. This is one of 
the methods by which Nature forces all living creatures to 
exert themselves mentally and physically. It is only by 
mental and physical activity that the evolution of life 
proceeds. 
FRESH-WATER SNAKES. 
The Fresh-water Snakes haunt the vicinity of rivers, pools, and 
marshes, swimming and diving with the greatest ease and grace. 
They live mostly upon aquatic creatures such as tadpoles, frogs, 
and fish. Specimens kept in captivity readily seize and eat 
small live fish placed in their water-pan. These snakes do not 
live habitually in the water. In fact, they only enter the water 
in search of prey. If a frog or fish be seized in the water, the 
snake will swim to land with it. I have seen Green Water Snakes 
carry frogs several yards up a sloping bank. The snake holds 
its prey in its jaws and raises the head and fore part of the body 
off the ground when thus employed. 
