306 
EEPTILES. 
[Chap. IX. 
especially when alarmed, affords evidence of the same 
faculty. 
The general characteristic of the Tree-snake is an 
exceedingly thin and delicate body, often adorned with 
colours exquisite as those of the foliage amongst which 
they live concealed. In some of the South American 
species the tints vie in brilliancy with those of the 
humming-birds ; whilst their forms are so flexible and 
slender as to justify the name conferred on them of 
" whip-snakes." The Siamese, to denote these combina- 
tions of grace and splendour, call them " Sun-beams." 
A naturalist 1 , describing a bright green species in Brazil 
(Philodrycbs viridissimus), writes : £f I am always de- 
lighted when I find that another tree-snake has settled 
in my garden. You look for a bird's nest, the young 
ones have gone, but you find their bed occupied by one 
of these beautiful creatures, which will coil up its 
body of two feet in length within a space no larger 
than the hollow of your hand. They appear to be 
always watchful ; for at the instant you discover one, 
the quick playing of the long, black, forked tongue 
will show you that you too are observed. On perceiving 
the slightest sign of your intention to disturb it, the 
snake will dart upwards through the branches and over 
the leaves which scarcely appear to bend beneath the 
weight. A moment more, and you have lost sight of 
it. Whenever I return to Europe, you may be sure 
that in my hot-house those harmless, lovely creatures 
shall not be missing." 
Ceylon has several species of Tree-snakes, and one of 
the most common is the green Passerita, easily recog- 
1 Dr. "Wtjcheker of Bahia. 
