144 THE ZOOLOGIST. 



might do so more appropriately. The phenomenon is really due 

 to the anterio-posterior flattening of the neck — if we may speak 

 of a snake's neck, for in anatomical law it has none ; this 

 flattening is brought about by the extension of the ribs : these 

 being extremely mobile in their articulation with the vertebrae, 

 and not fastened down to any breast-bone underneath, admit of 

 being drawn out at right angles to the spine, stretching the 

 skin and subjacent soft tissues to a corresponding extent. But 

 this power is actually limited in the specially-noted "hooded" 

 snakes in comparison to what it is in many others which flatten 

 their whole bodies, throughout the entire length to which the 

 sides are supported by ribs, in the same way! All snakes, indeed, 

 possess this faculty in some degree ; but striking examples of it 

 are afforded by the Puff-adder (Vlpera arietans), Liophis merremi, 

 and, perhaps above all, by the Leaf-marked Snake (Xenodon 

 rhabdocephalus). This last not only flattens its diamond-patterned 

 body until it becomes a mere ribbon, with the back-bone visibly 

 jutting up in the middle line, and possibly a recently-swallowed 

 frog sticking out like a tumour, but positively expands its 

 normally convex head in like manner ; so that the whole animal 

 looks as if a cart-wheel had passed over it longitudinally. This 

 hideous habit combined with its decidedly truculent aspect have 

 given it a bad reputation, and, in some places, the name of 

 " Spreading Viper," though it is quite harmless. 



In the absence, then, of any outward and visible sign to 

 lead us to infer with certainty the presence or absence of the 

 death-dealing teeth, there is only one way of making sure on the 

 point ; and that is, to open the snake's mouth and see if they are 

 there. Nor need anyone be alarmed at the idea of doing this ; 

 it is by no means difficult or dangerous. If a serpent be held 

 firmly behind the head — whether gripped in the hand, or pressed 

 forcibly on the ground with the foot, or held by a loop of string or 

 tape rove through an eye in the end of a stick (which is the very best 

 and safest way of catching them) — it will open its jaws of its own 

 accord and keep them widely distended in its efforts to bite, and 

 a deliberate inspection of the interior of the mouth may thus be 

 obtained. Perhaps an exception to this should be made in favour 

 of our common Ringed Snake, which, as far as I have seen and 

 heard, can never be induced to bite. Serpents allied to the Viper 

 and Rattlesnake have movable fangs, which will be seen to 



