THE TAIL OF A SNAKE, 179 



Thouo-h In form the ' neck ' of a snake is often as undis- 



o 



tinguishable as the tail — 'une tete sans col, et une queue, 

 dont I'origine se confond avec le reste du corps,' as Dumeril 

 expresses it — there is the one invariable rule belonging to 

 it, namely, that the first two joints of a snake's spine are 

 ribless, and that the ribs begin at the third. Physiologists 

 tell us a snake has no neck, and for reasons which will be 

 explained in the next chapter ; yet, by way of distinction, 

 all speak of * the neck ' as an accepted fact. 



No invariable rule as to tails can, however, be established, 

 either as regards length, shape, or character. Firstly, the 

 length of the tail varies from inches to feet in snakes of 

 nearly the same size. Secondly, both venomous and harm- 

 less ones are occasionally furnished with horny tips, and 

 both vibrate them with equal rapidity. Thirdly, snakes 

 that have long spineless tails also vibrate them rapidly ; as 

 do snakes with short spineless tails; so that one cannot 

 say that spines are confined to one genus, any more than 

 is their use or their action. The vibration of the tail is, in 

 fact, only 'an outlet for suppressed energy,' as Professor 

 Shaler of the United States has lucidly put it. Excitement 

 displays itself in the tail of a snake as much as in the tail 

 of a dog. This may be observed at the Ophidarium, or 

 wherever an active snake can be watched. In the rattle- 

 snake it is, of course, more conspicuous, and always audible 

 when agitated ; but many others similarly display their 

 feelings in their eloquent caudal terminations. 



A handsome young python, of about eight feet long, at 



other. He had the Rat-tail {Fer de lame) and two Cribos with others in one 

 cage, living on peaceful terms. 



