104 ANIMAL LIFE IN AFRICA 



was specific. This is now contradicted by scientific 

 experts, who hold that other causes are responsible. 

 While some are inclined to believe that the contrast in 

 colour may be due to surroundings, others think that green 

 is the colour of the young snake, and that he darkens 

 with age. The Sabi Bush is notorious for the number 

 of snakes it holds, and there are certainly more mambas 

 to the square mile there than in any other part of Africa 

 with which I am acquainted. They appear to be per- 

 fectly constant in colour i.e. olive black though I 

 saw a green snake, about eight feet long, with the ap- 

 pearance and unmistakable action of a mamba, take 

 refuge in a leafy tree upon one occasion. The bush 

 aforesaid consists of stunted acacias, interspersed with 

 sun-baked outcrops of granite rock, and there are few 

 cool and shady ravines capable of adequately and per- 

 manently sheltering any snake from the strong light. 



Those who support the theory that surroundings 

 influence colour, point out that the skin of a dead green 

 rnamba, if exposed to the sun's rays, quickly becomes 

 dark ; and if this holds good when the snake is still alive, 

 few individuals in the Sabi Bush would have any chance 

 of retaining the lighter hue. On the other hand, I never 

 remember noticing a black mamba under about seven 

 feet long, and I do not think it would be possible to con- 

 fuse a small one with any other species of snake, the 

 whole appearance and manner of moving are so different. 

 It is conceivable that the young may live entirely in trees 

 until they have attained a considerable size, preying on 

 small birds and their offspring. They would thus largely 

 escape attention, and so their universally green colour 

 would not be noticed. Some observers say that the 

 green mamba is a tree snake, while the black one is not. 

 I am in a position, from constant observation, to certify 



