_THE RATTLE._
THIS _Crepitaculum caude_, as an American has called it, has been the
theme of many speculations. Its origin and its use have been discussed
alike by the scientific and the unscientific, nor have they even now
arrived at any very definite conclusions on these two points. There
are theories as to its development, its form and size, its age and its
utility, the caprice witnessed in all of these adding to the romance
of its history; and whether its length increases by a link annually,
or on each occasion of desquamation, have been among the questions
connected with it. If we believe what the American Indians declare,
an additional joint to the rattle grows whenever a human being falls
a victim to that particular snake—a tradition more poetical than
rational. The Indians also think the rattle vibrates more in dry than
in wet weather, and are therefore cautious in traversing the woods
during rainy seasons. This belief has given rise to the idea that the
rattle is affected by damp—a fact which was affirmed so long ago
as 1722.[82] The most reasonable clue to this is, that there may be
less to disturb the reptile at a time when all animated nature is to a
certain extent inclined to retirement and repose; for if the reptile
be disturbed, rain or no rain, the rattle vibrates. In English as well
as in American scientific journals, the subject of the rattle is ever
and again ventilated by physiologists, and new suggestions are thrown
out. In the present chapter I will endeavour to give a sort of digest
of all these theories, venturing to offer in addition the results of my
own observations. Appended is a drawing of the first rattle I ever saw
or had in my possession. It is associated with a delightful visit of
several months to some very dear friends in Iowa, and it recalls more
particularly one lovely September afternoon. We were driving along a
wild country road, where the prairie on either side was radiant with
its floral carpet, and where the Mississippi gleamed like a succession
of lakes between the wooded and picturesque bluffs that formed the
background to the east.
Suddenly the horses refused to advance, and without any visible reason
to _me_; but the friend who was driving us recognised, in what seemed
to be merely a little dry twig in the middle of the road, nothing less
than a young rattlesnake.
Now, to see a rattlesnake and to hear its rattle had been the great
ambition of my prairie sojourn, and as my friend threw the reins to his
wife and alighted to deal a death-blow, I entreated him to spare it for
a few minutes only that I might examine and hear the as yet unfamiliar
appendage.
Alas! the creature had no rattle. ‘It is too young: there is only
the _button_,’ as my friend called the rudimentary promise of one. I
profited by the occasion, however, to have a good though disappointed
look, not unmixed with contempt, at the juvenile Crotalus, being so
very small and unworthy the ceremony. A foot or so in length, it began
to make its escape into the long grass, when by one quick stamp of his
heel our champion disabled it.
Then, throwing it into a pool of water, he remounted, and the horses
fearlessly proceeded.
[Illustration: A fully developed rattle of a rather small snake (life
size).]
A few days after this, to compensate my disappointment, I was presented
with a ‘full-grown rattle’ from a Kentucky snake, and here it is.
Asking how he knew it was ‘full grown,’ my friend explained that the
links being all of a nearly uniform size, proved that the snake had
also attained a certain growth during the development of that rattle.
This will be more readily comprehended on seeing the next specimen,
which is the rattle of a Mexican snake during early and rapid growth,
and a very perfect one, presenting no flaw or friction; proving that it
has not been subject to very long or very rough usage.
[Illustration: A very perfect rattle (natural size).]
In texture this is scarcely so stout as the shaft of a quill, nor so
pale, but almost as transparent. As regards size, the terminal link or
‘button’ may be compared to the nail of a young child, the intermediate
links gradually increasing with the growth of the snake to the nails of
older children, and the largest link to that of a full-grown person.
From the form of this rattle—an accurate copy of the original—we
may infer that it grew rapidly at first, and that the snake was large
during the development of the later links.
The next, reduced in size, is the rattle of a snake which had attained
full growth, but from which the younger or earlier links with the
terminal ‘button’ are gone.
[Illustration: Portion of a long rattle, much reduced in size.]
Extending this specimen by imaginary converging lines, we form an idea
of what its length might have been if perfect, probably about twenty
joints, which is a not unusual number; but we perceive at once that
a rattle, as we happen to see it, is no criterion of its age or its
original form. Rarely is a snake seen with a long rattle perfect and
entire. But whenever it gradually tapers and ends with the pointed
terminal link, we may decide that that rattle has escaped injury from
its earliest development.
In form it is not unsymmetrical, and in substance it is horny, like
hair, nails, quills, and hardened skin, a sort of dense and corneous
integument, yet less solid than horns and claws. The links, being
only interlocked and yet elastic, can be easily separated, and are
consequently easily injured. An animal treading on the rattle of a
snake would cause a portion at least to be lost; or in being drawn
among roots and entangled vegetation, a rattle might easily get
damaged: the number of links can never, therefore, be an infallible
clue to the age of the reptile.
Like hair, horns, nails, it is also subject to a caprice in growth,
or to the vigour of the individual; at one time comparatively at a
stand-still, at another growing rapidly; in one season gaining perhaps
several links, in another season none.
Neither does the number of joints bear any relation to the casting of
the skin, any more than the growth of hair or nails depends on the
healing of a scar. The slough, cast more or less frequently, may leave
the rattle intact, or a new link may appear at such a time. Dr. Cotton,
of Tennessee, had a rattlesnake which shed its skin on an average twice
a year, and he observed a new link to the rattle on each shedding.
On the contrary, a rattlesnake at the London Zoological Gardens,
and in the collection for about ten years, had never a rattle worth
mentioning. Quite a young snake of only 15 inches when brought, it grew
into a fine healthy specimen, fully five feet long, and yet had never
more than what Americans call the button—not quite even that, but
merely an abortive pretence of unhealthy growth, as if one or two links
were consolidated. I watched that rattle for several years with much
interest. Thus it was when my attention was first drawn towards it;
and though it sometimes gave promise of growing, and once did indeed
gain another link, it soon got broken off, and never attained more than
three misshapen joints.
[Illustration: All there was of it! From life.]
Though no rattle is ordinarily developed until the snakeling is some
months old, several cases are on record where young snakes have been
born with the ‘button,’ and even with perfectly formed links. Mr.
Benjamin Smith Barton, an American who wrote a good deal about the
Crotalus, communicated to Prof. Zimmermann in 1800 that he had found
in a parent some young ones with three rattles, _i.e._ ‘links,’ each.
Similar and more recent cases are on record.
[Illustration: Transparent rattle (p. 296), held against the light.]
In colour a rattle is of a dark brown, or dull rusty black,
occasionally lighter when fresh and uninjured, and then more plainly
displaying its horny texture. In the Mexican rattle (p. 296) the
links were semi-transparent; sufficiently so to enable us to trace
the form of the interior links if held against the light. This
afforded an admirable opportunity to comprehend the structure and
the production of the sound, which is simply and truly a rattling of
these loosely-fitting links as they are partially embraced, each one
by the previous link. That is to say, each new link grows up into
its predecessor, pushing it forward towards the tip of the rattle.
Through this unusually clear rattle you can trace each link passing up
and fitting into the preceding (prior) one, just as so many thimbles
or cups would fit into each other. Only, in the case of thimbles or
cups, there is nothing to keep them in place, and the slightest shake
would detach the whole pile; whereas the lobes or bulging sections of
each link prevent any such detachment in a rattle, except by force or
accident.
The next is the rattle of a small Oregon snake. This, as is
observable, is old and very much worn; so much so, indeed, that one has
to handle it with care. It is, however, pulled apart intentionally to
show that the links vary in form from those of the tapering specimen.
Any rattle can thus be separated without much effort, as, owing to the
elasticity of the substance, not much resistance presents itself. The
links are just loose enough to produce that sibilant effect, like the
rustling of dry leaves, or of ripe beans in a pod; or still more, like
the seed vessel of our own native plant the Yellow Rattle, _Rhinanthus
Crista galli_, and the American ‘Rattle-Box,’ _Crotalaria sagittalis_.
[Illustration: Small divided rattle.]
Yet just so securely fitting it is as to permit of the continual
vibration without loss of links.
What we _see_, therefore, is only the base or lower lobe of each joint,
the rest running up into the next two or even three bases, as may be
traced in the section here given.
[Illustration: Section of rattle.]
In reading about the construction of a rattle, some perplexity may
occur from the various adverbs before, behind, first, last, previous
link, etc., some referring to age, others to place. Descriptions
of the rattle met with in popular physiological works prove the
above perplexities, and verify what is so often demonstrated, viz.
the ‘inability of unscientific persons to read scientific matter
correctly.’ The ‘last’ link means the one last grown, not the end one
of the tail; ‘pushing the preceding one _forward_’ is not towards the
_head_ of the reptile, but literally _outward_ and _backward_ towards
the tip of the tail. ‘Previous’ may mean in time, or the age of the
link, or it may mean position; but a knowledge of the development
assists the comprehension of such passages.
In the above illustrations it will be seen that not only do rattles
differ in form in various species of snakes, but that the links
themselves differ in form in one and the same rattle. Some of them are
broader than others, some wider, and some more compressed. In all the
above drawings I carefully and faithfully copied the originals. And
in this variability we can only refer again to claws, nails, horns,
feathers, etc., which are seen to differ in the same individual,
according to health, season, or accident.
Where great numbers of rattlesnakes have been killed in one locality,
as, for instance, during the ‘spring campaigns,’ their tails
have presented on an average from fifteen to twenty links each.
Holbrooke[83] has seen one of twenty-one links. A Crotalus at the
London Reptilium had twenty-five links at one time; then ten of them
got broken off, but still a respectably-sized rattle remained. The
longer the rattle, the greater the risk of injury. Oliver Wendell
Holmes, in his wonderful story _Elsie Venner_, states that a snake
in the locality where the Rocklands ‘Rattlesnake Den’ existed, had
forty joints in its rattle, and was supposed, after Indian traditions,
to have killed forty people. He tells us that the inhabitants of
those parts were remarkable for acute hearing even in old age, from
the practice of keeping their ears open for the sound of the rattle
whenever they were walking through grass or in the woods. And whenever
they heard the rattling of a dry bean-pod, they would exclaim, ‘Lord,
have mercy upon us!’ the sound so strongly resembling that of the
dreaded Crotalus.
Another American naturalist records a snake with forty-four links
to its rattle, but adds that this occurrence is rare and ‘a great
curiosity.’ So one would imagine, and that the fortunate possessor of
such an ensign must have flourished in smooth places. More favoured
still was a snake mentioned in the vol. of the _Philosophical
Transactions_ just now quoted, and in which Paul Dudley had ‘heard it
attested by a Man of Credit that he had killed a Rattlesnake that had
between 70 and 80 Rattles (_i.e._ links), and with a sprinkling of grey
Hairs, like Bristles, all over its Body.’ As this venerable Crotalus
must have rusticated nearly two hundred years ago, we must accept the
tale or tail with caution.
The family of the _Crotalidæ_, it will be borne in mind, embraces a
large number of serpents with only a rudimentary rattle; a number with
only the horny spine (see p. 176); and a few with a rattle so small
even when fully developed, that they are received into the family by
courtesy rather than by their ‘sounding tail.’
[Illustration]
A small snake with this pretence of a rattle is dangerous because it is
so indistinctly heard.
This is also the case with _Crotalus miliarius_, whose rattle is so
feeble as to be scarcely audible a few feet off.
So much for the size of rattles. Now for the development of them.
The theory that the rattle is the remains of cast-off cuticle, as some
herpetologists have supposed, may be dismissed at once; for what would
cause such vestiges to harden into a complicated and symmetrical form?
To Dumeril we owe some of our best conceptions of the growth of the
rattle, which, whether it has or has not been evolved from the mere
horny spine that terminates the tails of so many snakes, has certainly
_now_ an express provision for its production.
Like hair, claws, or nails, the rattle is horny matter excreted and
hardened. In his _Elementary Lessons in Physiology_, Prof. Huxley
shows us how in the growth of a nail new epidermic cells are added to
the base, constraining it to move forward. ‘The nail, thus constantly
receiving additions from below and from behind, slides forward over
its bed and projects beyond the end of the finger.’ If the reader will
look at his finger nail, and suppose the end bone of the Crotalus spine
to be the ‘bed’ of the nail, he will to a certain extent be able to
comprehend how the rattle grows out; but that the links become detached
in succession is a phenomenon so astonishing and at the same time so
difficult to comprehend, that few naturalists have ventured to state
positively how this occurs. Conjecturally only and diffidently do I,
therefore, presume to offer a supposition; and if my readers will
once more pardon reference to human nails, and lend the aid of their
imagination, they may be able to evolve a true theory out of my crude
idea.
The young readers of _Aunt Judy’s Magazine_ were also, a few years
ago,[84] invited to lend the aid of their pink little finger nails to
the illustrative development of a supposed rattle; and we will again
imagine the whole tip of a finger to be covered with a round nail-cap,
proceeding from the first joint, and to have grown so from birth. In
growing out, this curious, cup-like nail, being never cut, would become
hollow like a thimble. Pointed or tapering it would of course be,
because, as the baby finger grew, the base or new portion of nail grew
larger with it. We will also suppose that the joint whence the nail
sprang was in constant activity, and so articulated that it _could_
move with a quick and regular action or vibration; the hollow nail-cap,
having attained a certain size, would become withered, and (as the
constant bending of a piece of card or metal in time divides it) would
be worn, and at length detached at its base. Meanwhile the growth of
nail has not been arrested, but a new cap is forming within. The old,
dry, and withered cap has now nothing to retain it, and would drop off,
on account of its simple, conical form, like a loose-fitting thimble.
But Dumeril explains to us that the terminal bones of the rattlesnake’s
spine present a peculiar form, several of them coalescing.
‘Dans les Crotales cette extremité de la queue, au lieu d’être
pointue, se trouve comme tronquée, et, par une bizarrerie que nous
n’expliquons pas, il paraîtrait que les trois dernières pièces de la
colonne vertébrale se seraient soudées entre elles, et comme aplaties
pour composer un seul os triangulaire, avec trois bourrelets latéraux
simulant des restes d’apophyses transverses des vertèbres, ainsi
qu’on les voir souvent dans les trois dernières pièces du coccyx
chez l’homme. Cet os anormale a été disséqué chez un Crotale, on a
reconnu qu’il est recouvert d’une sorte de matière cartilagineuse dans
laquelle aurait été secretée la substance cornée, comme un epiderme
solide, qui conserve en effet extérieurement la forme de la pièce
osseuse, sur laquelle elle a été en quelque sorte moulée et qu’elle
semble destinée ainsi à protéger contre l’exfoliation, comme cela
s’observe dans ceux des animaux ruminants dont la corne revêt les
chevilles osseuse du véritable coronal prolongé en pointe et devenu de
cette façon une arme d’attaque, et surtout de defence.’[85]
Dumeril also tells us that the peculiar structure of those few terminal
vertebræ, with their knobs or pads (‘_bourrelets_’) upon which the skin
is moulded, tends to a movement lateral rather than up and down,—that
quick action which we perceive when the rattle is being vibrated.
Thus the horny covering takes the form of this bone with its lobes
or bulges, which instead of permitting the supposed cup-like nail to
fall off as in our finger illustration, causes the links as they are
pushed out to hang or cling together; and we can only suppose that the
constant action loosens, and not only loosens when dead or detached,
but loosens, that is to say, enlarges, the link while growing. For if
you examine the spine of a skeleton Crotalus and the rattle that grew
upon that spine, you will perceive that the links are a great deal
larger than the ‘_pièce osseuse sur laquelle elle a été en quelque
sorte moulée_.’
There is one other peculiarity observable in a detached rattle, which I
cannot pretend to explain in any way. If you hold one up by its base or
largest link, you will find it invariably hangs in a slight curve and
not perpendicularly. You can straighten it, but you will not be able to
curve it in the opposite direction, proving that it naturally inclines
one way, whether to the right or the left of the animal while living, I
cannot assert. But it is a curious feature, and one that can no doubt
be accounted for by scientific observers. Thus, as in the illustration
below, you can curve a rattle so as to discern the interior links on
one side, but not on the other. I have made the attempt with many
rattles, but always with the same result. The centre fig. below is a
section.
[Illustration: Natural position when held.
Straightened by force.
This fine specimen, natural size, and also the Tapering Rattle, both
from Mexico, were lent to me by J. G. Braden, Esq. of Lewes, and copied
accurately.]
Not the least important of all the speculations to which the rattling
tail has given rise, is the question, ‘Of what use is it?’ for we know
that nothing exists in vain. Apart from the fact that the American
savages make some medicinal use of the rattle, this elaborated,
curious, and not unsightly instrument has as yet had no special and
determined office assigned to it to the advantage of its possessor,
though theories regarding it are numerous.
Formerly, when only the dangerous powers of the reptile were
understood, it was sufficient to say of it in a tone of pious
thankfulness, that the Almighty had so armed this serpent as a warning
to its enemies. Some of those early writers introduce the rattlesnake
to us as the most benevolent and disinterested of dumb animals,
conscientiously living up to his duties, obedient to that ‘peculiar
Providence’ which has given him a rattle ‘to warn the inadvertent
intruder of danger.’ ‘He maketh such a noise that he catcheth very
few,’ an evidence of imprudence wholly inconsistent with his inherited
‘wisdom.’ Indeed, between the character given of this ‘superb reptile’
by Chateaubriand, and the self-sacrificing qualities assigned it by
some other writers, we can only wonder how a hungry rattlesnake ever
managed to survive at all, and how it is that the race is not extinct
long ago.
That the early and unscientific travellers, speaking from a thankful
experience of having escaped a rattlesnake through _hearing_ where
it was, should seek no further for the utility of the rattle, is not
much to be wondered at. But so lately as 1871 one of our popular
physiologists, whose work is a textbook, has expatiated on this
theme so positively that it is necessary to quote his words on this
‘admirable provision of nature,’ which apparently has elaborated a
unique appendage for the purpose of starving its proprietor!
‘The intention of this organ is so obvious, that the most obtuse
cannot contemplate it without at once appreciating the beauty of the
contrivance.... It (the snake) announces the place of its concealment,
even when at rest, to caution the inadvertent intruder against too near
an approach.’[86]
If all the venomous serpents were thus beneficently armed (the cobras
of India especially), the crusade against snakes would be at an end, or
never need have been instituted; for supposing the heedless loiterer to
have been a bird, squirrel, guinea-pig, or any of the lesser mammalia
which form the food of most snakes, these happy creatures would have
had the world to themselves long ago, while vipers had kindly starved
themselves out of all traces.
‘Every creature of God is good,’ we must repeat and ponder over. Even
a deadly rattlesnake, and every part of that rattlesnake, has its
appointed use.
The ‘inadvertence’ (in this instance on the part of the writer who thus
expressed himself) has not been without its use as well, for a more
careful attention has been given to the rattle in consequence; and much
controversy has since arisen among some of the ablest herpetologists,
particularly in America, where much that was new and suggestive soon
found its way into the scientific journals.
Briefly to summarize some of the arguments, I will repeat a few of them
as suggested by some well-known naturalists. In that able periodical,
the _American Naturalist_, vol. vi. 1872, the subject was thoroughly
discussed. Professor Shaler, in a paper on ‘The Rattlesnake and Natural
Selection,’ admitted that whereas he had hitherto thought and taught
that the rattle did more harm than good to its owner, he now knew that
the sound is so similar to that of the stridulating insects upon which
some birds feed, that he had no doubt of its use in attracting these
to the snake. He himself had mistaken the sound for a locust. ‘Does
it invite its enemies or entice its prey?’ he asks. ‘Those snakes
that can best attract birds, are best fed.’ In reply to this, a Mr.
J. W. Beal of Michigan affirmed that he had often mistaken the sound
for grasshoppers; which educed many similar accounts from persons who
had been in danger of treading on a Crotalus through ‘inadvertent
approach,’ supposing that only an insect were there. A child had taken
it for a cicada, some one else for a locust, etc. Any one who is
acquainted with the wild parts of the American Continent, is familiar
with the ceaseless chirps and whizzings of those ubiquitous insects
which are furnished with the stridulating apparatus, and which lead you
almost to expect to see a scissors-grinder behind every tree. These
are all the more deceptive on account of their varying cadences, now
louder, now softer, approaching or receding, just as the sound of the
rattle varies by increased or less rapid vibrations, or according to
its individual size and strength. In a paper read before the Zoological
Society by Mr. A. R. Wallace in 1871, he invited attention to this fact
of the resemblance between the sound of the rattle and the singing of a
cricket, and that its use seemed to be to decoy insectivorous animals.
Dr. Elliott Coues is also of this opinion, viz. that to an unpractised
ear the sound cannot be distinguished from the crepitation of the large
Western grasshopper. A case has been reported, he tells us, of a bird
observed to be drawn within reach, thinking it was a grasshopper. Dr.
Coues also affirms that the sound has been heard when no perceptible
irritation disturbed the snake.[87]
Thus we see that the ‘inadvertent intruder,’ so far from being warned
away, is beguiled to his injury, both in the case of human beings not
quick to discriminate sounds, or not having rattlesnakes in their
minds, and with animals in their early experience who perhaps hear one
for the first time.
Another question is, ‘Does the snake sound its rattles when seeking to
capture prey?’
The editor of the _American Naturalist_ in the volume already quoted,
thinks they do not systematically set up a rattling for this purpose;
and as far as observation of snakes in confinement can be of use, this
opinion may be confirmed. Probably a captive snake may have learned
by experience that, hungry or not, it must wait for its periodical
dinner, and that its ‘dinner bell’ avails it nothing. Nevertheless, we
do not find that the snake uses its rattle upon food being placed in
its cage, unless the rat or the guinea-pig come tumbling unexpectedly
or unceremoniously upon the snake, when it would sound its rattle in
alarm; but it waits quietly, silently, rather receding than advancing
towards the destined prey, and then, after cautious observation,
stealthily approaching to give the fatal bite. Mr. Arthur Nicols,
author of _Zoological Notes_, etc., has there discussed this point,
but dismisses it by declaring he has no faith in ‘the dinner-bell
theory.’[88]
Nor can the rattle be designed to terrify enemies or as a menace, since
the sound would invite the attack of those very animals which the snake
has most cause to fear, namely goats, hogs, and the large carnivorous
birds that devour it. If, besides, it were used as a warning, why have
the young ones, which are more in need of protection, no rattle?
Darwin, in the sixth edition of his _Origin of Species_, 1872, writes
as follows, p. 162:—
‘It is admitted that the rattlesnake has a poison-fang for its own
defence and for the destruction of its prey; but some authors suppose
that at the same time it is furnished with a rattle for its own injury,
namely to warn its prey. I would almost as soon believe that the cat
curls the end of its tail when preparing to spring in order to warn
the doomed mouse. It is a much more probable view that the rattlesnake
uses its rattle, the cobra expands its frill, and the puffadder swells
whilst hissing so loudly and harshly, in order to alarm the many birds
and beasts which are known to attack even the most venomous species.
Snakes act on the same principle which makes a hen ruffle her feathers
and expand her wings when a dog approaches her chickens.’ This profound
thinker, then, is one of those who include the rattle among ‘the many
ways by which animals endeavour to frighten away their enemies.’
We may reasonably conclude that the _Crotalus_, in common with other
snakes, also with dogs and cats, expresses a variety of feelings with
its sounding tail, fear being the most predominant one. The Indians
recognise its utility as a warning by gratefully abstaining from
killing one that rattles. They superstitiously regard it as protective
to themselves if not to the snake, and they in turn carefully protect
the reptile. Backwoodsmen display little or no fear when they _hear_
the _Crotalus_, and though they do not spare it, regard it with less
bitter animosity than they display towards its cousin the Copper-head;
because, as a facetious writer has testified of it, ‘it never bites
without provocation, living up to the laws of honour, and by his
rattles giving challenge in an honourable way.’
That the sound has a language of its own is known by the fact that
when disturbed and one rattle is sprung, all other rattlesnakes within
hearing take up the chorus. That the sexes also understand each other
through crotaline eloquence is generally believed. In fact, to each
other and to themselves they have, no doubt, as many variations in the
use of their rattles, as any other animal in the expression of its
tail; and probably all the above enumerated examples are at one time or
another its legitimate uses. Those who have most closely observed them
have detected a variety of cadences in one and the same rattle.
Those also who have carefully watched rattlesnakes under various
circumstances, must perceive that timidity is one of the strongest
features in this reptile. In chap. xxx. I will give examples of this.
Already convinced by observation, I attributed to excessive timidity
the chief agitation of the rattle, when writing on the Ophidia in the
_Dublin University Magazine_, December 1875, and again in _Aunt Judy’s
Magazine_, July 1877. Fear causes some snakes to puff themselves;
others to expand or flatten the body; fear excites the cobra to erect
its anterior ribs and display its ‘hood;’ and, above all, fear causes
most snakes to hiss. Fear is coupled with anger, in these attempts
to do their best towards repelling the offender. Dr. E. Coues, in
speaking of the rattle, supposes it to have possibly ‘resulted in the
course of time from the continual agitation of the caudal extremity
of these _highly nervous and irritable creatures_.’ Dr. Weir Mitchell
has known captive snakes to vibrate the rattle for hours at a time;
and probably, if there were opportunities of becoming more intimately
acquainted with crotaline idiosyncrasies, we should discover some
snakes to be more or less afflicted with temper, nervousness, terror,
or other emotions which induce an animal to express its feelings in its
own way.
But the most remarkable peculiarity in this snake is that no other
way _is_ in its power: _a rattlesnake never hisses_. Throughout the
numerous arguments, theories, explanations, and suggestions, there is
such an absence of allusion to this fact that we must suppose it to
be very little known. Says Dumeril in describing _les petits étuis
cornés, comparé à celui que feraient plusieurs grelots peu sonorés:
‘Les Crotales diffèrent de tous les autres serpents connus par la
faculté qu’ils ont de produire des sons sourds et rapides, cu plutôt
des bruits continus et prolongés à l’aide d’un organe spécial, qui
supléerait—pour ainsi dire—à la voix, dont ces serpents sont toujours
privés.’_[89] But the sibilations of the rattle are often so like
hissing that they have been compared to the whistling of wind among
the leaves, to the escape of water through a pipe, to the whizzing of
insects, the rattling of seed pods, and many similar sounds, showing at
the same time the character of the noise and its variability.
Concisely recapitulating what this rattle does, we understand that in
the first place it is a substitute for the voice—so far as hissing can
be called voice; and that what would cause other excessively nervous,
timid, terrified snakes to hiss, causes the rattle to vibrate. It may
attract insectivorous birds; it may alarm other timid creatures; it
may summon its mate; and, as is well known, it has sympathy with its
mate; for a second rattle is almost sure to be sounded, and they have
been observed to sound in pairs or numbers responsively—it may be
to express anger, fear, and for aught we know _pleasure_, in a state
of liberty and enjoyment, feelings expressed by the tail of other
creatures.
Why it is formed as it is, so wholly different from all other tails;
from what it has been evolved; and how long in evolving,—all these are
problems to be solved by future Darwins and future Evolutionists.
This chapter, therefore, closes with only feeble speculations after
feeble attempts to explain an inexplicable phenomenon. The simplest and
truest solution seems to be found in those few words, ‘_qui supléerait
à la voix, dont ces serpents sont toujours privés_.’
Again, we wonder whether in the non-hissing serpents any peculiarity of
trachea may be observed.
[Illustration]
[Illustration]