198 THE SNAKES OF SOUTH AFRICA. 



Mr. Jones has counted over sixty eggs, large and small, in a 

 single snake. Mambas are very sociable, several males and 

 females being frequently found inhabiting the same hollow in the 

 trunk of a tree, a crevice among boulders, or a hole in a bank. 

 Mr. Jones tells me he has found as many as half a dozen pairs 

 inhabiting the same hole. He says they have no objection to 

 residing beside the true Cobras, as he has often found Black 

 Mambas and Cobras {Naia nigricollis) sharing the same retreat. 

 I have found them at times with other species of snakes in the 

 broken and abandoned hills of Termites (" White Ants "). 



How AND Why they Change Colour — A Theory. 



The female Mamba lays its eggs in hollow tree trunks 

 and in holes in banks in the dense bush, where the young, 

 when hatched, will have fewer natural enemies than if in 

 more open localities. The young take to the trees, and would, 

 most likely, haunt the woodlands until nearly adult, when the 

 struggle for existence becoming keener, they or many of them, 

 would wander further afield for food, which had hitherto been 

 chiefly birds, their young and eggs, chameleons and other tree 

 lizards. On leaving the dim, moist, and shady forest, and 

 venturing out into the open country, the strong actinic rays of 

 light from the sun would very soon cause the vivid green pigment 

 of the skin to assume an olive tint, which would subsequently 

 darken and become the characteristic colour of the Black Mamba. 

 In Mamba infested forests in Zululand where Black Mambas 

 abound, there are many open bare spaces upon which Black 

 Mambas bask in the hot sun. This habit of lying exposed to the 

 strong rays of sunlight might have been a contributing cause to 

 the determination of their colour. 



Green, especially the more vivid shades, is rapidly acted upon 

 by strong white light. The fresh skin of a Green Mamba, if placed 

 in a strong light, will rapidly change to blue or olive, then to 

 olive-black. If dried in a dark place, rolled up and packed away, 

 it will retain its green colour. 



It is stated there are males and females amongst the green 

 and black varieties of Mambas, and that eggs have been found in 

 both varieties. 



The question of colouration in snakes is a very puzzling one. 

 We find Mole Snakes [Pseudaspis cana) of several colours. Some 

 are uniform shiny black, others are reddish-brown, brownish- 



