Dr. Otto Wucherer saw this in a South American snake, Xenodon colubrinus. ‘It has the habit of striking the ground rapidly with the tail when irritated’ (Zoo. Soc. Proc. 1861).
So do Spilotes variabilis, and some others. So also does the Pine snake, whose tail ends in a horny tip, ‘like a four-sided spike,’ and which vibrates like a crotalus in rudiment, or strikes the ground.
Several American naturalists have contributed interesting accounts of this last species, known as the ‘Bull’ or ‘Pine snake,’ or ‘Pilot snake,’ the largest of the N. American Colubers. It was this species (Pituophis melanoleucus) whose actions Mr. Sam. Lockwood described as mystic circles, and its activity as almost equal to that of the ‘Racer’ (American Naturalist, vol. ix. 1875). But it is called the Bull snake because it ‘roars like a bull.’ Bartram went so far as to say like thunder! ‘Said to hiss like thunder,’ or ‘resembling distant thunder,’ is the cautious testimony of Holbrooke, who adds, ‘but I never heard it, though well acquainted with it.’
Mr. Lockwood minutely described one in his possession. In reading his account we can but notice the similarity of action between this ‘Bull snake’ and the African vipers in ‘puffing,’ though regarding the nature of the sound, the writer positively affirms that ‘there is nothing sibilant in this blowing, not the slightest hiss about it.’ Mr. Lockwood records his experience of several that he had seen and heard, and of a fight between one and a rat. ‘Now began that fearful blowing. The snake slowly fills its lungs with air, and then expels it with a bellowing sound that is really formidable.’ And again, in the same volume, in reference to the former account, he says: ‘As there noted, the Pituophis, when alarmed or enraged, slowly inflates itself with air, thus nearly doubling its normal size along its entire length, except the tail. It then slowly expels the air with its own peculiar sound.’ He recalls his boyish terror on once hearing this sound, which came upon him suddenly in a field, ‘like the restrained roaring of a bull.’ This was in New Jersey; but the Pituophis family extends to the Western States, and to the Rocky Mountains, where ‘Bull snakes’ are frequently seen. In the reports of the United States Exploring Expeditions, mention has been made of the prairie Bull snake, and of others in Nebraska and as far west as California.
Some attain to seven feet in length; Holbrooke mentions one of nine feet, and ‘as thick as your arm,’ in common parlance. An angry snake of this size could, of course, blow with considerable force, and the term ‘bellowing’ might not unreasonably be applied to the sound; as it is also applied to the croaking of the ‘bull frog’ (Rana mugiens), the sound of which is really so like the lowing of cattle, that, on hearing one for the first time in the woods of Virginia, I looked round, quite expecting to see a young heifer in close proximity.[44] Probably, had the bovine lungs sounded at the same moment, the reptilian ‘bellow’ would have proved but a feeble imitation. A sound out of place, so to speak, or unanticipated, strikes upon the ear more forcibly than when expected. But if one reptile, and that a very small one, can so well imitate a bull as it is universally known the bull frog does, why may not another do the same?—an argument which I venture to use notwithstanding many herpetologists accept doubtfully the possibility of a snake producing such a sound. ‘Il est difficile à concevoir comment les serpents auraient la faculté de siffler, comme on pretend que peuvent le faire certaines espèces de couleuvres, et comme les poëtes se plaisent à nous les representer. Jamais nous n’avons pu entendre qu’un soufflement très sourd, provenant de l’air qui sortait avec plus ou moins de rapidité de l’interieur de leur poumon que l’on voyait s’affaisser en trouvant une issue par la glotte, à travers les trous des narines ou directement par la bouche dont la mâchoire superieure est naturellement echanchrée. Alors la bruit était seulement comparable à celui qui resulterait du passage rapide et continue de l’air dans un tube ou par un tuyau sec et etroit, comme serait celui d’une plume.’[45]
This no doubt answers to the ordinary ‘hissing’ of the majority of snakes; but that the sound varies under certain conditions, and in the same serpent, cannot be denied. A. R. Wallace relates an incident which may well be introduced here, as affording both a proof of the length of time snakes can sustain a sort of half suffocation, and also the expression or power of ‘voice’ in breathing. A young boa was caught, and in order to prevent its escape, its captors, while preparing a box in which to convey it away, tied it tightly round the neck to a thick stick, which not only fettered its movements, but appeared to nearly stop its respiration. It lay writhing in much discomfort, sometimes opening its mouth with a suspicious yawn, as if trying hard to breathe. By and by, when relieved from its clog and safely consigned to a box with bars on the top, it began to make up for loss of time by breathing violently, ‘the expirations sounding like high-pressure steam escaping from a locomotive. This continued for some hours, of four and a half respirations a minute,’ when the breathing—in this case we may say panting—gradually subsided, and then the poor thing settled down into silence.[46]
The expression of feelings by the tail in so many snakes, producing a sibilant sound in rustling dead leaves, and in some which are supposed never to hiss, is a subject well worth the attention of scientific naturalists. It would be interesting to ascertain if any peculiarity of trachea or of glottis exist in these.
