But now we come to the most amazing of all the wondrous detail of this living hypodermic syringe. Those who have seen a viper or a rattlesnake strike its prey, are cognisant of the lightning-like rapidity of the action. So swift is it that often a spectator is not sure whether the snake touched the victim or not. A flicker, a flash, and the bite has been given. Dr. Mitchel, describing the singular inactivity of rattlesnakes in confinement, points out the striking contrast between this repose and the perilous rapidity of their stroke. Now let us look at the amount of business transacted in that flash of time. Says Dr. Elliot Coues: ‘The train of action is first reaching the object; secondly, the blow; thirdly, the penetration; fourthly, the injection; and fifthly, the enlargement of the wound (the latter by dragging upon it the whole weight of the body by the contraction of certain muscles, which cause the fangs to be buried deeper and thus enlarge the puncture); and all these five actions accomplished in that instantaneous stroke!’ This is what Fayrer means when explaining that ‘the real bite is when the snake seizes, retains its hold, and thoroughly imbeds its fangs.’ ‘Sometimes the lower teeth and the palatine become entangled (and sometimes a fang is left in the wound).... The force of ejection may be seen when a serpent striking violently misses its aim, and the stream has been seen to spirt five or six feet. A blow given in anger is always accompanied by the spirt of venom, even if the fangs fail to engage.’ ... Another curious piece of mechanism, and one not previously described that I am aware of, is a provision for the fangs when they fail to bite. ‘A serpent always snaps his jaws together, and thoroughly closes them when he strikes; therefore, if the fangs failed to engage, they would penetrate the lower jaw. But there is a certain movement among the loose bones of the skull (perhaps not yet thoroughly made out), the result of which is to spread the points of the fangs apart, so that they clear the inner sides of the under jaw, instead of injuring them.’ Coues here describes rattlesnakes particularly, but no doubt the same extends throughout the viperines.... ‘In a large snake the entire gland may be an inch long and one-fourth as wide, having the capacity of ten or fifteen drops of fluid. There is no special reservoir for the venom other than the central cavity of the gland. Formerly there was thought to be such a storehouse; but when the tooth is folded back, certain muscles press or compress the canal to prevent a wasteful flow: in other words, the communication is shut off!’
In this wonderful exhibition of the ivory hypodermic syringe there has not, I trust, been so much repetition as to render the subject tedious. Presented in such graphic language and from such a source, it must attract almost every intelligent reader, while the viperine fang is absolutely acting before his eyes. On this subject, then, no more need be said; though on the Crotalus family generally some interesting matter still remains to be told.
CHAPTER XXI.
THE CROTALIDÆ.
IN the several chapters in which the rattlesnake has been introduced, the reader has seen that for about 250 years it has been an object of interest and of study among naturalists, and that first one and then another has made fresh examinations of its various parts, giving to the world new items of information as the results of such observations.
And can there remain anything further to find out about it? we may ask in surprise. Yes, there is. There yet remains to comprehend and decide upon one feature which thus far has defeated conjecture and investigation—the ‘pit’ (p. 277). Possibly among the indefatigable observers in the land of rattlesnakes, recent labours may have been rewarded by some new evidence of the utility of this peculiar orifice, and already their zoological journals may have enlightened ophiologists on its functions. At the present moment I am not aware of such information; and time will not permit of further delay to enable me to send a message of inquiry across the great deep.