THE XE NO DONS. 403 



and vexation I passed my little finger along the jaws and 

 felt the upper teeth. 



This practical investigation no doubt greatly offended 

 the imprisoned patient, for suddenly down came a pair of 

 regular fangs — they looked like fangs ; — and as my finger 

 pressed the jaw on one or on the other side, I saw these 

 fang-like teeth move, vibrate, exactly like the viperine 

 fangs. When my finger was removed, up they went, folded 

 back in their sheath in true viperine fashion. My finger 

 got a slight prick, for they were exceedingly sharp ; but 

 know^ing there was no venom in them, that did not concern 

 me, and in a few minutes the sensation was gone. But how 

 was it that Dr. Stradling had made no mention of this 

 extraordinary viperine mobility of the fangs ? And what 

 kind of jaw must a snake have to move its back teeth in 

 this manner ! For we saw in the previous chapters that 

 the mobility of the fangs is in proportion to the diminishing 

 length of the maxillary bone, that the excessive mobility 

 of the viperine fang is owing to the greatly reduced size of 

 that bone, that a slight mobility is observable where the 

 jaw is somewhat less reduced, and so on ; but here is a 

 harmless Coluber with a jaw long enough to hold five or 

 six fixed, simple teeth, and then an extremely mobile long 

 one at the back. Can the jaw be divided in the middle ? 

 Thus I marvelled. 



* Now let us look at Heterodon.' 



But that pretty little snake positively refused to open its 

 mouth ; so, fearing to alarm it, or cause it to disgorge its 

 last meal, I did not encourage its forcible detention. 



Not to lose a moment, I then and there pencilled a note to 



