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238 SNAKES.

as well as by the absence of horns. The upper surface of the head is covered with
scales, and the keeled scales of the body form from twenty-live to thirty -five rows.
The common desert saw-viper, or, as it is called in Egypt, eja (Echis carincfn),
attains a length of about 2 feet ; and has the keels on the lateral scales of the body
strongly serrated. In colour it varies from pale buff to greyish, reddish, or pale
brown on the upper-parts, with three series of whitish spots edged with dark
brown, in addition to which there may be a dark brown zigzag band along each
side, while the head is ornamented with a cross or arrowhead mark ; and the
under-parts are whitish, either with or without brown dots. This species inhabits
the desert regions of Northern Africa, South-Western Asia, and India, being
replaced in Arabia and Palestine by E. colorata.

The most remarkable peculiarity of this viper (which, however, it may possess
in common with the horned vipers, since the scales of the latter have a similar
structure) is its power of making a curious, prolonged, almost hissing sound,
produced by rubbing the folds of the sides of the body one against another, when
the serrated lateral scales grate together. That this is the true cause of the
sound may be proved by twisting the body of a dead specimen, and thus causing
friction between the scales. Sir J. Fayrer writes that this species is a very fierce
and vicious viper ; it throws itself into an attitude of defence and offence, coiled
up like a spring, rustling its carinated scales as it moves one fold of the body
against another. It is aggressive, and does not wait to be attacked before darting
its head and body at its enemy, the mouth wide open, and the long fangs
vibrating, thus presenting a most menacing appearance. It is very poisonous,
and there can be little doubt that it destroys many human lives, as men are
much more exposed to contact with this species than with Russell's viper.

The dreaded rattle-snakes of the New World are our first repre-
sentatives of the subfamily of pit-vipers (Crotalina'), which, are
common to Asia and America, and are characterised by the presence between
the nostril and the eye of a deep pit in each loreal shield, the physiological
significance of which is still unknown. All have triangular broad heads, and
short thick bodies. The Asiatic representatives of the group are less deadly
serpents than their American relatives; while the only vestige of the rattle of
the latter to be found in the former is a small horny spine at the end of the tail
of one species. Many of the Indian species are arboreal in their habits ; their
coloration assimilating to that of the foliage and boughs among which they
I well. As regards their geographical distribution, pit-vipers present a curious
similarity to bears and deer ; and since they are most abundant in the Oriental
region, and also more numerous in North than in South America, Mr. Wallace is
of opinion that the group originated in the Indo-Chinese countries, and thence
spread north-eastwards to North America, and so onward to the southern half of
the New World, which area, having been the last to receive the group, has not
had time, in spite of its extreme fitness for reptilian life, to allow it to attain its
full development.

The rattle-snakes are sufficiently distinguished from their allies by the
jointed horny appendage at the end of the tail from which they derive their name.
In the young rattle-snake the tail terminates in a somewhat nail-like " button,"



VIPERINE GROUP,



239



which in a perfect rattle remains at the tip, the various rings, which may reach to
twenty or more in number, being gradually interpolated between this and the
2aly portion of the tail. More or less symmetrical in form, the rattle is composed
of hollow, horny rings, somewhat like quill in substance, which are interlocked
with one another, and are yet so elastic as to allow of a considerable amount of
motion between them. The various rings do not appear to be formed with any
regularity, sometimes several being added in a single year, while at other seasons
but one is developed ; neither does there seem to be any relation between the
growth of the rattle and the changing of the skin. That very large rattles must,
however, belong to old snakes, is obvious ; and that this is really the case is shown
the circumstance that at the present day rattles with twenty rings are very




COMMON RATTLE-SNAKE (\ liat. size).

sldom met with, since with the advance of cultivation it is only rarely that these
)xious reptiles are suffered to attain their full age. The body is thick, and,
for poisonous snakes, somewhat long; and the poison-glands attain very large
dimensions.

Common Since the rattle-snakes are extremely variable in coloration,

Rattle-Snake, reliance has to a great extent to be placed on the arrangement of the
shields covering the fore-part of the head in the discrimination of the species. In
the common rattle-snake (Crotalus durissus) of North America, the distinctive
character is the presence of only two pairs of large shields between the large
supraocular and rostral shields ; these paired shields being separated by a series
of small ones in the middle line. Of these shields, behind the large triangular
rostral comes the four-sided anterior pair, representing the anterior frontals, while
to each of the latter further back joins a larger oval shield which must be regarded






2 4 o SNAKES.

as a lateral remnant of the hinder frontal. The space between the two last-named
shields is occupied by a series of small shields, of which the front ones are the
largest: and between the supraocular shields commence the long keeled scales
covering the body, where they are arranged in from twenty -five to twenty-seven
longitudinal rows. The ground-colour of the upper surface is a dull greyish brown,
upon which are two rows of large, irregular spots, which may unite into zig/ag
crossbands, and are gradually lost on the dark tail ; the under-parts being yellowish
white, marked with small black dots. Generally about 4i feet in length, this
species may grow to 6 feet.

Diamond In the Southern United States the commonest member of the

Rattle-Snake. g enus i s the diamond rattle-snake (C. adamanteus), represented in
the upper figure of the accompanying illustration, which is not only the most
beautiful, but likewise the largest species, adult females (which in this group are
always larger than the males), not unfrequently measuring 6 feet in length.
From the common rattle-snake it may be distinguished by the large and narrow
head, on which the shields are but slightly developed, the presence of three pairs of
shields between the rostral and supraocular on the top of the muzzle, by the scales
of the body being always arranged in twenty-seven rows, and also by the coloration.
The small rostral shield is markedly triangular, the slightly developed frontal has
a roundish pentagonal form, and the great supraocular shield a distinctly over-
hanging edge. After shedding, the new skin is of a beautiful greenish, or
occasionally golden-brown, ground-colour; upon this is a triple lozenge-shaped
chain-pattern on each side of the back, the golden yellow lines of which stand out
in marked contrast to the dark diamonds of the ground-colour. A black i si i brown
band runs from the muzzle through each eye to the corner of the mouth ; and the
top of the head is either uniformly coloured, or ornamented with irregular markings.
South American Of the six species of the genus, four are confined to North
Rattle-Snakes. America, and only one is found to the southward of the Isthmus of
Panama. The latter species (C. horridus), which is represented in the lower figure
of our illustration, approaches the common species as regards the arrangement of
the shields on the head, while in coloration it is like the diamond rattle-snake.
From the former it may be distinguished by the circumstance that the two pairs of
shields between the rostral and the supraocular have no small shields between
them, so that they come in contact with one another in the middle line ; while from
the latter the larger size of the lozenges on the body, and the presence in each of
a light-coloured centre will serve as a sufficient distinction, in addition to the
different arrangement of the head-shields.

In noticing the habits of these snakes our remarks will chief! v
Habits.

relate to the North American species. As we have already said,

rattle-snakes chiefly frequent dry and sandy localities, more especially when they
are covered with bushes ; but we have to add that in North America they fre-
quently take up their abode in the burrows of the prairie-marmot. Formerly it
was thought that the snakes and marmots lived together in harmony, but it is now
ascertained that the former prey on the young of the latter. The general food of
rattle-snakes consists of small mammals, birds, lizards, and frogs, the latter being
especial favourites ; but mammals as large as a mink have occasionally been taken



VIPERINE GROUP.



241



from them. The most extraordinary peculiarity connected with the common
species is its habit in the colder regions of North America of collecting in enormous
numbers for the winter sleep. In some districts the snakes used to assemble in
hundreds, or even thousands, from all sides to sleep in the ancestral den, some of
them, it is said, travelling distances of twenty or even thirty miles. Huddled
together in masses for the sake of warmth, the serpents passed the winter in a
state of more or less complete torpor, until the returning warmth of spring once
more started them to spread over the country. When rattle-snakes were abundant,
annual or biennial hunts used to take place at these dens; the fat of the
slaughtered reptiles being used as a valuable supply of oil. Catlin tells us how,



DIAMOND AND SOUTH AMERICAN RATTLE-SNAKES




nat. size).



when a boy. he once assisted at one of these hunts at a place known as Rattle-
snake Den. whence the snakes used to come forth on to a certain ledge of rock in
swarms. At one time, he says, there was a knot of them " like a huge mat wound
and twisted and interlocked together, with all their heads like scores of hydras
standing up from the mass," into which he tired with a shot-gun. Between five hundred
and six hundred were killed with clubs and other weapons, but hundreds more escaped
to the den. Fortunately one large one was taken alive, and was made the means of
destroying the rest, a powder-horn with a slow fuse being applied to its tail, and
the reptile allowed to crawl back to the cave, where a loud explosion soon told the
tale of the destruction that had taken place.

The most interesting point in connection with rattle-snakes is the use to which
the appendage from which they derive their name is put, for use it must surely

VOL. v. 1 6



242



SNAKES.



have. The old view was that it was intended to warn creatures preyed on by
these reptiles of the approach of their enemy ; but, in regard to this supposition,
Darwin well observes that " 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 rattle-snake uses its rattle, the cobra
expands its frill, and the putt-adder swells while 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." In this
passage the writer commits himself to the view that the rattle is an instrument of
intimidation. It may, however, be observed that the sound would be quite as




THK BUSHMABTBB (! nat si/u).



likely to attract enemies as to repel them. Moreover, it is now a well-ascertaim
fact that rattle-snakes do not possess the power of hissing ; and as that facult
seems more closely connected with fear than with any other emotion, it would
quite reasonable to suppose that the rattle stands in place of the hiss. Anothc
feature in the controversy is the circumstance that the sound of the rattle of 01
snake causes all its kindred within hearing to sound their own: and tin- or;
therefore probably serves as a means of communication. What is known
the "dinner-bell" theory, that is, that a rattle-snake attracts insects like gra
hoppers and cicadas within striking distance by the resemblance of the soui
of its rattle to their own stridulating utterances, has been pretty el earl
disproved ; while if it required a further quietus, the circumstance that the
reptiles do not appear to prey habitually upon insects would be sufficient.



VI FERINE GROUP.



243



the whole, while admitting- that fear has probably some share in the matter, it
seems better to suspend our judgment before definitely committing ourselves to
any one particular view. That rattle-snakes are some of the most deadly of all
venomous serpents may be freely admitted ; and it seems that we must almost
concede that they possess the mysterious power of " fascinating " their victims
before striking. Moreover, the assertions as to the power possessed by vipers of
swallowing their young are equally numerous and well-authenticated in the case of
the serpents under consideration.

The formidable South American snake (Lachesis muta) known
The Bushmaster. ( .

to the Dutch settlers of Guiana as the bushmaster, but by the

Brazilians termed the surukuku, differs from the rattle-snakes by the presence
of a distinct keel-like ridge down the back, and, in place of a rattle, having the
under surface of the tip of the tail covered with from ten to twelve transverse
rows of small, spiny, sharp scales, while the extremity terminates in a spine.
This snake attains a length of from 9 to 12 feet, and has the ground-colour of the
upper-parts reddish yellow, upon which is a longitudinal row of large blackish
brown lozenges, each having two light spots on either side of the middle line ; while
the under-parts are yellowish white, with a porcellanous glaze. The large size and
enormous poison-fangs of the bushmaster render it one of the most formidable
of the pit-vipers ; its bite being apparently fatal to human beings in a few hours.
Fortunately it is far from common, and inhabits only the secluded portions of the
primeval forest, where it lies coiled up on the ground. Unlike most snakes, when
disturbed it makes no attempt to flee, but strikes with the rapidity of lightning at
the disturber of its slumbers.

These snakes have the upper surface of most, or all, of the front
Halys Vipers.

of the head covered with large shields ; the body is rather long

nd clothed with from seventeen to twenty-seven rows of keeled scales; and
the very short tail has its lower shields arranged in either a double or single series,

)ine species having a small spine at the extremity, which is regarded as a
^udimentary rattle. The genus is common to Asia and North and Central

Lmerica ; some half-score of species being known, two of which are found in India.

)ne species ranges as far east as the Urals, where it just enters the confines of

Europe. In habits they are all terrestrial.

Himalayan Of the Indian species, in both of which at least the majority of

Halys. the shields on the lower surface of the tail are arranged in two rows,
the Himalayan halys (Ancistrodon himalayanus) is distinguished by having two
pairs of large shields on the muzzle, the extremity of which is but little turned
upwards. In colour it is brown, with black spots or transverse bands, while some-
times a light festooned stripe runs clown the back ; from the eye to the angle of
the mouth runs a black streak edged with white ; and the under-parts are either
dark brown, or variegated with black and white. This snake, which grows to
nearly a yard in length, is abundant in the North- Western Himalaya, at elevations
of between five thousand and eight thousand feet, although it sometimes ascends
considerably higher. The carawila (A. hypnale), of Ceylon and Western India, is
a much smaller species, not exceeding 20 inches in length, and characterised by the
extremity of the upturned muzzle being covered with small scales.



244



SNAKES.



Siberian Halys.



Somewhat superior in size to the common viper, this species (A.
kalys) may be recognised by the small portion of the head that is
covered with shields, and also in that each shield, or pair of shields, overlaps with
its hinder edge the shield immediately behind it, thus producing a more or less
marked imbrication of the whole of the head-shields. Another characteristic is to be
found in the small size of the anterior frontal shields, which together have a crescentic
shape and a somewhat saddle-shaped upper surface. The head is very distinctly
defined from the compressed neck, the body being rather long, of a rounded trian-
gular form in the middle, and covered with twenty-three rows of triangular scales :
the very short tail, which is much thinner than the hinder-part of the body, is
conical, and armed at the extremity with a forked horny appendage. The ground-







SIBERIAN HALYS VIPER (^ nat. size).



colour of the middle of the back is a dark brownish yellow grey, while that of the
under-parts is a yellowish white, with more or less well-defined black spots on the
hinder shields. The yellow ground of the labial shields of the head has chestnut-
brown markings; and the crown of the head bears a large quadrangular blotch,
forming an interrupted transverse band on the frontal shields, and a temporal hand
running from the hinder border of the eye to the angle of the mouth and the side
of the neck. Somewhat similar markings ornament the back, and are more or less
clearly margined with yellow. Along the whole length of the back and the ridge
of the tail are a number of yellowish or yellowish white black-edged irregular
blotches or crossbands; and on the sides are two rows of blackish brown spots
with white edges, which frequently run one into another, the first dark spot on
the neck differing from the rest by its horse-shoe form. The distributional area of
this snake extends eastwards from the Volga to the Yenesei. In Europe the halys



VI FERINE GROUP.



245



viper inhabits the steppes between the Volga and the Urals ; but its true home
is Central Asia.

copper-Head In North America, one of the best known and most widely

Snake. distributed members of the genus is the copper-head, or moccasin-
snake (A. contortrix), which seldom much exceeds a yard in length. The body is
strong and thick, the short tail provided with one row of shields inferiorly and
with a heavy appendage at the end, while the elongated triangular head is markedly
distinct from the neck, with the pits on the snout rather shallow, and the gape of
the mouth very wide, and there are no small smooth shields behind the large
parietals. A beautiful coppery brown, becoming lighter on the sides, forms the




COPPER-HEAD, OR MOCCASIN-SNAKE (-? nat. size).

ground-colour of the upper-parts ; upon which some sixteen reddish brown dark-
edged bands, becoming wider on the flanks, have given rise to the name of
moccasin-snake. On the under-parts the shields are copper-red, marked on the
sides with large polygonal or rounded alternating dusky spots. The head is
generally lighter coloured than the body, and marked by a broad stripe running
from the snout along the side to the angle of the mouth. The distribution of the
copper-head extends from the 45th parallel of north latitude to the extreme
south of the Eastern United States. Its favourite haunts are damp situations,
more especially shady meadows covered with tall grass ; and its food consists of
mice, birds, and probably frogs. From its abundance and comparatively rapid
movements, as well as from its lacking the warning sound of the rattle, the copper-
head is even more dreaded than the rattle-snake.



246



SNAKES.



Water-Viper.



Another well-known North American representative of the genus
that must conic in for a brief share of attention is the water- viper (A.
piscivorus), which inhabits marshes, rivers, and lakes, and attains a length of
nearly five feet. From the preceding species it may be distinguished by the
presence of two small smooth supplemental shields behind the parietals, and of
numerous small scales between the hinder frontal and temporal shields. The colour
is very variable ; but in the majority of specimens, on a shining greenish grey
ground, there are a larger or smaller number of dark bands somewhat similar to
those of the copper-head. Always found in the neighbourhood of water, this
snake extends southwards from North Carolina over the whole of North America




CLIMBING FiT-vii'Kit (\ iint. size).

and westwards as far as the Rocky Mountains. Feeding chiefly upon fish and
frogs, it will also devour all animals that may happen to fall into the water and
are not too large for its maw ; while in the rice-fields it is the dread of the negroes.
Not only is the water-viper feared by man, but it is shunned by all animals
dwelling in or near water.

Typical Pit Under this title may be included the members of the largest genus

Vipers. o f ^he subfamily, which is likewise common to Tropical America and
Asia, and is the last group of snakes that we have space to mention. These pit-
vipers are long-bodied snakes, characterised by the whole of the upper surface of
the triangular head being covered with scales instead of shields; the tail, which is
frequently prehensile, ending in a sharp point, and having either one or two rows



PIT- VIPERS.



247



of shields on its lower surface. In all the Asiatic species there are two rows of
these subcaudal shields, and it is only in a few of the New World forms that they
are reduced to a single series. The number of longitudinal rows of scales on the
body is very variable in the different species, ranging from as few as thirteen to as
many as thirty-one. In Asia these snakes range from India to the South of China
and the Liu-Kiu Islands ; and while some species are terrestrial and normally
coloured, others are arboreal, and in the greenish tints assimilate to the colour of
their surroundings. The climbing tree-viper (Trimeresurus gra/mincns) belongs
to a group of four allied Indian and Burmese species, characterised by their




RAT-TAILED PIT- VIPER (J liat size).

prehensile tails and the arrangement of the scales on the body in from thirteen
to twenty -three rows ; the figured species usually having twenty-one rows of scales,
while there are from seven to thirteen scales in a transverse series on the head
between the supraoculars; the temporal scales are smooth, and the shields on the lower
surface of the tail vary in number from fifty-three to seventy-five. Attaining a
length of 2i feet, this snake usually has the upper-parts bright green, although in
some specimens they may be yellowish, greyish, or purplish brown, while they may
or may not be marked with black, brown, or reddish spots. Generally there is a
light-coloured or reddish streak along the outer row of scales, and the end of the
tail is frequently red or yellow; the under-parts being green, yellow, or whitish.
Ranging from Bengal to the Malayan region, this species is thoroughly arboreal in



248 SNAKES.

its habits. Stoliczka states that he found these snakes very common about the
limestone-hills near Moulmein, where they are exactly of the same green colour as
the foliage amongst which they hide themselves. He saw small specimens very
often on low umbelliferous plants growing about a couple of feet high. One of the
snakes had its tail wound below round the stem of the flower on the top of whirl i
it was basking. All were very sluggish, and did not make the slightest attempt 1"
escape when approached, and even allowed themselves to be removed from the top
of the plant. Neither did they offer to bite, unless when pressed to the ground
with a stick ; but when thoroughly aroused, they turned round and bit furiously
The rat-tailed pit- viper, or fer-de-lance (T. lanceolatus) is one of several American
species with nonprehensile pointed tails, whose habits are terrestrial. Beaching a
length of nearly 7 feet, with a body as thick as a man's arm, this snake is very
variable in coloration, the ground-colour of the upper-parts being generally a
reddish yellow-brown. The distinctive markings take the form of a black stripe.
which is but seldom absent, running from the eye to the neck, and of two rows of



Online LibraryRichard LydekkerThe new natural history (Volume 5) → online text (page 26 of 62)