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United States Department of Agriculture

Bureau of Biological Survey

Washington

POISONOUS SHAKES OF THR UNITED STATES
Prepared in the Section of Food Habits, Division of Wildlife Research

—-—-—

Contents

Page Page

Ine GGnae ON Heme Vey ass Mh ioyi)e 1/5) iye We 1 ; Treatment for bites of North
Key to the principal poisonous : American poisonous snakes. aa
snakes of the United States. Saens DEM VS stOrwehe) VUCtATC ce. - dbal
Names anc ranges of the : (MeN G OMNC One SiG uae ier. = atle) A) us wil
MAUECSMECS) ils ws « % eo Brel Other first-aid measures . . Tal
Poison epveratus of venomous : Ad@itional treatment .... 2

SUA eOSpaeiieelere Se x 6 Special directions for the
POAS PREPARES ei cieernto Nec? vere 6 My SL CHAM as.) ao ee Spe os 15
en rae Ole SULOKe Vielen) a- i 9s Cais PEL DGE CAME TOMS: lake! lente: \ aS
Venoms of poisonous snakes .. . (e MOn Rens aller Gy er Rey eee eas, Con oe ECE cs 1
Mortality resulting from snake Bl GROW teME'- , ghlp ot. cise) Coa 's1 8 14
DER CUeeE gums pe. wauattueey ls \ edie SIR Wr goyovsnsuee) HO) TAvbeunm OMG NOME or ono 14
Snakes committing suicide. ... oe! JNO! akalonyiesia Gg tae SOMe amy acrat ALS
Oy 16H Uopeactepolanil 5 woleom ae ouro Monel 'c IS)

INTRODUCTION

Snakes are easily confused with one another, and the question as to
whether a certain one is poisonous or hermless arises again and again. Out
of about 205 species and varieties of snakes tnat occur in the United States
and Lower California, less than 15 percent cen be considered dangerous to
mene Poisonous snakes are provided with a specific venomous fluid and an
apparatus especially adapted for the introduction of this poison into their
victims. As it is usual to regard all snekes as venomous, the burden of
proof is upon those believing in their innocence. So many wonderful stories
concerning snakes have been current from time to time that the public in
turn becomes skeptical about everything concerning snakes or firmly believes
in traditional accounts that usually are highly erroneous. Allowance being
made for misinterpretation of certain natural habits of reptiles, the grain
of truth may be perceived in these traditions in spite of the exaggeration
that ordinarily accompanies a good snake story. Nevertheless, poisonous
snakes are an actual as well as a mental hazard in these days of hiking,
camping, and auto picnicking.

The coral, or harlequin, snakes (Micrurus and Micruroides) are
members of the cobra family (Elapidae) that have become adapted to a
subterranean existence, and occur from South Carolina and Arizona to South
America. They have solid, rigid fangs with a groove on the front surface
and are rrequently confused with the nonvenomous scarlet snake (Cemophor2
coccinea) and scarlet king snake (Lampropeltis elepsoides). The former dif-
fers from the harlequin snake (and also from the scarlet king snake which
it resembles very closely) in having the ventral surface yellowish white;
the scariet king snake differs from the harlequin in having the black cross
bands less than half the width of the crimson.

The Crotalidae, or "pit vipers", have hollow fangs that fold back

t the roof of the mouth when the jaws are closed. They occur through—
emperete and Tropical America and include a number of venomous species
that are familiarly known by the following names: Rattlesnakes (Crotalus),
massasauga (Sistrurus), cotton-mouth water moccasin (Agkistrodon piscivorus),
and copperhead (Askistrodon mokasen). Wo true vipers are found on the
American continents. The well-knowm rattlesnakes,-of which there are a
number of species, are the most specialized of all the venomous snakes. ‘The
rattlesnake race has been extraordinarily adaptable, as its members have
come to occupy the most diverse conditions of cay isonnenty including ex>-
tremes ®cth of humidity and aridity. “hes

The southeastern diamondback waione Areiee (Crotalus adamanteus) is
also known as the vater rattler because it is partial to the neighborhood
of water and is a good syimmer; yet others, the pallid rattler (Crotalus
mitchellii),for example, live in typical deserts. The prairie rattler
(Crotalus c. confluentus) occurs over the gryisn areas of the Great Plains,
ete a related form, the banded rattlesnake (Crotalus horridus), is limited
to tne timbered areas of the eastern parts. of the- United States. It is
certain that rattlesnekes do not habitually climb trees, because they are
poorly adented to such an accomplishment, yet there is unquestionable
proof that they do so occasionally. It reduires but little more climbing
ability to scale a rough-barked slanting tree than the face of a rocky ledge.

The pigmy rattler and massasauga (Sistrurus) are diminutive forms of
rattlesnakes (Crotalus), the largest atteining a length of nearly three feet
anc a thickness of less than one inch; their range is chiefly east of the
Rocky iiountains, except for Arimwnea, and they are characteristically forms
of the prairies and their swemps and marshes. Tne diamondback rattlers
(Crotalus adamanteus and C. atrox) are unquestionably the most excitable and
danzerous of all Yorth American pit vipers. The red rattler (Crotalus exsul)
is said to be the most sluggish. The cotton-mouth water moccasin frequents
the lovlands along the southern rivers and the adjoining swamps into which
the rivers overflow curing high water; when surprised it throws its head back
and opens its mouth, disclosing the white lining. In the Northern States
the copperhead is partial to rocky places inthe vicinity of timber, marshes,
or abandoned stone quarries; in the South it frequents higher and drier
ground than around the marshes; unless cornered, this snake usually attempts

“eV

to escape unseen. Nevertheless, the coppernead is a ratner dangerous snake,
giving no ywearning of its presence, and striking in any Girection.

Another small group of mildly poisonous snakes is found along the
Mexican border of the United States. They have grouved teeth in the rear
of the upper jaw and can scareely be considered dangerous to man. ‘This
group includes the Jews-harp snakes (Trimorphodon spp.), the annulated
snake (Leptodetra septentrionalis), the black-banded snake (Coniophanes
imperialis), and the Oxybelis (Cxybelis microcghthalmus). A genus of
diminutive snakes known as the black-headed snakes (Tantilla spp.) also
belongs to this group and occurs throughout the southern half of the United
States. The last-named snakes are so small and have such minute fangs that
they are totally harmless to man.

Key to the Principal Poisonous Snakes of the United States

._Smooth=-scaled snakes, characterized by brilliant colors; markings consisting of
broad alternating rings of crimson and pees separated from each otner

by narrower yellow rings; black bands as broad as the crimson; a pair of
snort, erect longitudinally grooved nee in front of upper jaw; head
SMCS Meek icine ie oss 49 ee nCOLal OF Marlicguim. snakes——l GAP LDA.

Head black infront, a yellow band across center and behind this
a black ring; yellow body rings very narrow. Most common in the
Gulf States, but extending north to North Carolina, and in the
lilssissippi Valley casually northward to Indiana and Ohio
Sede cea corel. or harlequin, snake——Micrurms tulvaius.

Head black over greater portion; yellow band on back of head
and benind this a red ring; yellow stody rings broader.
southern New Mexico, Arizona, Tiburon Island in the Gulf of
California, and northern iexico in region bounded by Rocky
Mountains and Colorado River.
rete eee see eeeess..e-Sonoran coral snake-—Micruroides euryxanthus.

Keel~scaled snakes, characterized by duller colors; markings not forming
regular alternating bands, but consisting of blotches, Giamonds,
or incomplete bands; a pair of long, hollow, freely movable fangs
that fol@ back against roof of mouth when jews are closed; deep pit
on face between nostril and eye; scales on upper parts keeled;
pupile elliptical in shape, vertical in positien; head wider than
ORE Saka keds Soi od begaabSbervicciorcsesoenees* Ele vepers'!—CROTALIOAR,

Tail without rattle, ending in a point; top cf head covered
with ESM oto anche) oh elle) et sliel of) 2 eile)\e) 1 ¢)(o1 » ale) el ene) e)~)\e (ela) 9 oe) e alee LSU LOCO.

Color pattern distinct; ground color pale brown (in Texas grad-
ing into pale green on tail), with large dorsal blotches
of darker chestnut brown (usually in the form of a butterfly
with outspread wings). Massachusetts to northern Florida,
westward to Illinois, Kansas, and Texas.
seeesseee--CODPErhead, highland moccasin, chunkhead,
poplar leaf, or deaf adder--Agkistrodon mokasen.

Color pattern obscure; ground color light to dark brown;
cross bands darker, often indistinct and bordered
with yellow spots; some of ventral scales on tail
undivided. Lowlands from southeastern Virginia to
Florica and the Gulf States northward through the
Mississippi Valley to southeastern Missouri and
southern Illinois.
»-e+.+--Cotton-mouth water moccesin—--Agkistrodon piscivorus.-

(Panel anristilar sett O%itscn Saiere «Norse cust cote see ene enters eRe -- Sistrurus and Crotalus.

A single large scale on top of head between supre-
=) S Ae
ocular scales (those over eyes). «cee... son = sos mH umUMater

Sige small (adults usually less than 20 inches
long); ground color grayish; lerge black
blotches on back, smaller series on sides.
Southeastern North Carolina to Florida, west
through the Gulf States to western Texas and
Oklahoma, and northwerd through Mississippi
basin to Arkansas.
eeeeececeeescGround rattler or pilemy ratile—
_ sneke--Sistrurus miliarius.

Size medium (adults usually 25 to 35 inches
long); ground color browmish; large black
blotches on back in close formation. Cen-
tral New York and Pennsylvania to south-
eastern Minnesota and southwestraré through
western Texas and New Mexico to northeast—-
ern Mexico (usually in moist situations).
ete eee c ec erecevees eMassasauga—Sistrurus catenatus.

Many small scales on tov of head between supraocular
scales’ (those! over eyes) oi fish ateleleve's lc w late olele ole tytate Oremnteimlene

Nemes and Ranges of the Rattlesnakes

All the large rattlesnakes and sever2l of the small species
belong to the genus Crotalus, of which 16 species or subspecies
(including 12 that are considered specifically distinct) are recorded
from the United.States in the 1933 Check List of North American Reptiles,
by Drs. Stejneger and Barbour. he characteristics distinguishing these
closely related rattlesnakes are too technical for presentation here.
The scientific and vernacular names and statement of the ranges of the 12

species follow:

Crotalus adamanteus--Diamondback rattler.

About swamps from southern North Carolina to Florida an

anc westward to Louisiana and Arkansas.
Crotalus atrox--Vestern diamondback rattler.

Dry rocky places as well as agricultural districts from Texas and
northern Mexico to Arizona; Colorado and southern California; and
Lower California.

Crotalus cerastes—--Horned rattlesneke, or sidewinder.

Sancs of desert plains in northeastern Lower California, southern
California, southwestern Utah, southern Nevada, and Arizona.
Crotalus confluentus--Prairie rattler (and other common names for more west—

ern forms).

British Columbia to Lower California and eastward through the Great
Plains from southern Canada to Texas.

Crotalus exsul-—-Red rattlesnake.

Southwestern California, Lower California, and islands in the Gulf of
Cailiskornid.a),

Grotalus horricus--Banded, or timber, rattler.

In yoody and hilly districts from Maine to Georgia, westward through
Louisiana to the Gulf region of Texas, and northward through the
ilississippi Valley to southeastern Minnesota and adjacent Wisconsin.

Crotalus lepidus--Green rattlesnake.
Mounteins from border region of western Texas to southern New Mexico,
Arizona, and adjacent Mexico.
Crotalus mitchellii--Pallid, or bleached, rattler.
Arizona, Colorado Desert to southern Lower California.
Grotalus molossus--Dog-faced rattler, or black-tailed rattler.
west from southern Texas to southern Arizona, and the highlands of
northern Mexico.
Crotalus tigris--Tiger rattler.
Southern California, southern Nevada, end southern Arizona.
Crotalus triseriatus--Spotted rattler.
Mountains of southern Arizona, and through the central plateau of Mexico.
Crotalus willardi--Rattler.
Santa Rita Mountain region, Arizona, and northern lfexico.

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FOISON APPARATUS OF VENOMOUS SNAKES

The fluid, or venom, is injected into the snake's victim by means of
Specialized teeth on the maxillary bone of the upper jaw, wich differ from
normal reptilian teeth in having a groove, or canal, from base to apex.

These venom fengs in tne dangerous species are large and readily observed.

The canals of the fangs are fed with fluid through ducts from the poison
glands. Venom does not flow freely except when the snake is actually striking,
for the end of the duct, which is not in contact with the base of the fang,

is normally compressed by a sheath, or fold of mucous membrane. A rattlesnake
may open its mouth to the fullest extent yet may or may not erect the fangs.
The snake apparently has perfect control over its fangs, raising or depressing
them at will. The venom is injected by the combined action of several muscles,
which open the mouth, erect the fangs, compress the poison glands, and thus
force the venomous fiuid through the connecting duct into and through the

fangs in the brief space of time in which the snake strixes its victim.

At the end of a stroke the fangs of a poisonous snake are quickly
withdrawn from the flesh; the whole action is the work of an instant. Unless
the snake strikes again, the mouth closes as the fangs fold back, mechanical
compression constricts the excretory duct, and pressure is relieved from
the poison glands by relaxation of the enveloping muscles. A pnoisonous snak
often miscalculates the distance of the object at which it is striking. In
case the object is too close, the fangs are not fully erect when the snake
strikes and hence do not penetrate. Conversely, if the thing struck at is
beyond reach, the whole stroke may be completed without touching the object
of attack. In this case it may happen that the venom is projected several
feet, an action that has given rise to repeated accounts of our poisonous
Snakes spitting venom.

In human beings the bite of a venomous snake is usually followed by
Painful symptoms and occasionally by death. Other animals are affected in
various ways. The hog, for example, has a degree of immunity from the bite
of venomous snakes, because of its thick skin and protecting layer of fat.

Poison Fanzs

Jo lets

Though the fangs of our crotaline venomous snakes are shed frequently,
it cannot be seid that they are shed periodically. On each side of the
upper jaw there is a hollow or grooved poison fang firmly ankylosed to the
maxillary bone. This pair of functional fangs is supplemented by several
pairs of smaller teeth growing loosely in the flesh and buried in the soft
sheath of the gum. When from any cause one of the large fangs is broken off,
the reserve fang nearest to it soon moves over in its place, grows fast to
the maxillary bone, ond becomes the functional poison fang. In case of
accident to either of the fangs in use there is always a reserve fang ready
to replace it.

Length of Stroke

The idea that a venomous snake can strike its full length or evena
greater distance is another popular but erroneous belief. When a snake

re ae

strikes from its usual S-shaped position, the anterior half of the body,
which is thrown forward, must be free from coil. [In striking, the snake
simply straightens out the S-shaped curves. Jt does not have to be in this
position to strike, for observation has shown that when irritated most of
our poisonous snakes can strike for short distances from alnost any position.
The western diamondback rattler, when excited, frequently raises its head
and the S-shaped loop 10 to 15 inches above the ground, from which position
it strikes sideward and downward. When this rattler is lying coiled with
its head resting on its body, it is able to strike almost vertically up-
ward. The greatest length of stroke is about three-fourths the length of
the snake, but few snakes strike more than half their length.

VaNOMS OF POISONOUS SNAKES

Venom is a secretion of a supralabial gland that resembles in its
development the parotid (s salivary) gland in mammals. It is composed of
50 to 70 percent proteins; the chief remaining components are water and
carbohydrates, with occasional admixtures of abraded epithelial cells, or
Saprophytic micro-organisms, while salts such as chlorides, phosphates of
calcium, magnesium, and ammonium occur in small quantities. The reaction
of venom to litmus is usually acid; in some cases, neutral. The venoms of
the different species of poisonous snakes differ to a greater or lesser
degree, although all venoms are multiple in nature, that is, they contain
Several toxins that act independently of one another. Warm—blooded animals
are usually more susceptible to venom than cold-blooded ones. Dried venom
retains its original toxic properties in unaltered strength and quality for
an indefinite period. Dr. S. Weir Mitchell found that venom kept dry for
25 years was unaltered in these respects. When fresh, the venom of a snake
is a somewhat viscid fluid of a yellowish color.

The effect of venom on the victim is due to the complicated action
of several toxic elements, of which neurotoxins and hemorrhagins (explained
tater) are the most important. WNeurotoxins have a destructive action upon
the nervous system and play the most important part in producing the death
of a victim of venom ynoisoning. They are present in relatively large
proportions and are the chief death-dealing factors in the venom of the
harlequin snakes (Micrurus and Micruroides), which belong to the cobra
family (Elapidae). In contrast, rattlesnakes (Crotalus and Sistrurus) and
moccasins (Agkistrodon) of the family Crotalidae produce neurotoxin in
comparatively small quantities. The venom of the cotton-mouth water moccasin
contains more neurotoxin than that of the rattlesnake, and consequently its
paralytic effect on the respiratory center and motor nerves is stronger.
This toxin not only breaks down the nuclei of the ganglion (nerve center)
cells, but produces Zranular disintegration of the sheath (myelin) and
fragmentation of the conducting portions (axis cylinder) of the nerve fibers.
These neurotoxins offer a high resistance to heat and retain their toxic
properties after prolonged treatment with alcohol.

The hemorrhagins constitute the chief toxic elements of rattlesnake
Venom and have a solvent action on the endothelial cells composing the
walls of the blood and lymph vessels, particularly the smallest of them
known as capillaries. One of the most alarming symptoms ensuing from the
bite of a pit viper is the enormous swelling and extravasation of blood

es ees

around the wound. The blood escapes from the blood vessels through holes
in the walls, for the walls of the vessels are really dissolved in places.
Red blood cells as well as white escape upon dissolution of the walls of
the blood vessels.

The venoms of different species of snexes dissolve the red blood
cells also in a similar fashion. This cell-dissolving substance, which
has a peculiarly destructive effect on red blood celis, is called hemolysin.
In dogs inoculated with venom the hemoglobin contained in the red blood
cells readily crystallizes. It has been found in animals dying from
retention of urine, after being bitten, that the tubules of the kidneys
are often completely blocked with hemoglobin crystals. The activities of
the white blood cells (leucocytes) also are suspended by the action of
the venom. Moreover, it has been found that venom contains elements that
are agglutinating es well as dissolving for the white cells and that these
are distinct from those that affect the red blood cells.

Biochemical studies have shown that snake venom possesses four dis-
tinct classes of ferment-like substances apart from the cell dissolvers
(cytolysins). These are the fibrin ferment and the proteolytic, diastatic,
and lipolytic enzymes. One of the most remarxable effects of both rattle-
snake and mocassin bites is the loss or the reduction in ability of the
blood to coagulate; it has been found that venom contains a powerful ferment
that attacks tne fibrin (the coagulating element) of the blood. The
proteolytic enzyme of snake venom softens the muscles; the diastatic enzyme
activates the inactive pancreatic juice, enabling it energetically to attack
albuminoids; and tne third enzyme has a ae lipolytic (fat dissolving)
action in sylitting lecithin and in causing fatty degeneration in the liver.

The quantity of venom yielded at any one time by our venomous snakes
varies, in general, in proportion to the size and age of the snake, the
length of the period of fasting or hibernation, and certain environmental
conditions. The pit vipers never inject the entire contents of their
glands at a single thrust, the amount injected varying from 25 to 75 percent
of the total, usually being about 50 percent.

Mitcnell published the following observations on the quantity of
venom yielded by four rattlesnakes:

Length, 18 inches; weight, 9-1/2 ounces; capacity of gland, 11 drops.

Length, 25 inches: weight, 18 ounces; capacity of gland, 19 drops.

Length, 49-1/2 inches; weight, 2 pounds 2 ounces; capacity of gland,
29 drops.

Length, 8-1/2 feet; ejected 1-1/2 drams of venom at single bite.

The actual quantity of venom injected into a victim depends largely
on the size of the snake, the length of time during which its supply has
been accumulating, the depth to which the fang is thrust into the flesh,
and the location of the bite. In the majority of cases human beings recover
without any treatment, because the quantity of venom injected is not a fatal
dose.

Mitchell repeatedly pointed out the danger of secondary bacterial

a Ye

infection in victims surviving the primary effects of snake poisoning, and
W- H. Welch, in 189%, discovered that rattlesnake venom causes blood to
lose its bactericidal power. Normal blood serum destroys thousands of
bacteria, wnile venomized serum does not possess this power.

Some xnowledge of the action of crotaline venoms is of greatest
importance to American physicians, as 99 ee of the cases of snake
bite treated in the United States are caused by pit viper At the present

time extensive experimental use is being made of the venoms of the cobra,
vipers, and crotaline snakes in the alleviation of the pain accompanying
Malignant growths such as cancer and in the treatment of arthritis. One
of the great possibilities of the use of venoms in medicine undoubtedly
lies in the ability of certain of the venoms to accelerate coagulation of
haemophilic blood.

MORTALITY RESULTING FRCM SNAK# BITE

The average mortality from bites of the American venomous snakes
was eStimated by Willson in 1908 as little more than 10 percent of those
bitten, but with modern methods of treatment fatalities have been reduced
to less than 4 percent. <A study carried on by ‘the Antivenin Institute of
America under the direction of Afranio do Amaral (1927) has shown, however,
that the danger from snake bite has been underestimated. It was found that
in the course of one year (July 1926 to June 1927) in Texas something like
150 cases were reported. Of these, antivenin was given in 83 cases, with
78 recoveries and 5 deaths, the death rate being 6 percent. The death
incidence was nigher than would have been the case had the antivenin been
administered sooner. In the remaining 67 cases, in which the antivenin was
not injected, 25 died, the death rate being 34.3 percent. In the North-
eastern States it has been estimated that the mortality rate, in the
absence of special treatment, is 10 to 18 percent of those bitten, the
increase being largely due to the copperhead. In Georgia, Florida, and
Alabema the average mortality is 18 to 25 percent. In Texas, New Mexico,
and Arizona the death rate is somewhat higher, no doubt because of the
presence of the western diamondback rattler (Crotalus atrox uO) Is and ranges
from 25 to 35 percent of those bitten. Estimates ranging from 100 to 1,500
cases in the United States each year of persons bitten by venomous snakes
show the present uncertainty that exists in regard to the prevalence of
aceidents of this sort.

The tendency of rattlesnakes to rattle whenever disturbed and to
continue the rattling as long as the disturbing influence is present also
ezplains why victims are not more numerous. The timber rattler has been
known to keep up its rattle for half an hour with but few intermittent
momentary pauses. The fact that the water moccasin lives in unfrequented
Swamps and the harlequin snakes have burrowing habits and small-sized mouths
accounts for the infrequency of bites attributed to these species.

In. fatal cases the time intervening between the bite and death varies
Sreatly. Cases terminating fatally within a few minutes do occur, though
fortunately they are very rare. There is a record (Roberts) that a boy
% years old bitten by a rattlesnake on the cheek below the eye pitched
forward dead before an eye witness could reach him. A little girl 3 years

SEH ale

old bitten on the forehead by a large rattlesnake died within 10 minutes
(Blackwood). An analysis of 50 fatal cases resulting from the bites of
American venomous snakes showed that 8 persons died in less than one hour,
13 between 1 and 6 hours, 18 in 1 to 24 hours, 4 died on the second day,

4 died between the third and seventh day, 1 at the end of nine dsvs, 1 at
the end of seventeen days, and 1 after more than a monty. The duration of
illness following snake bite is subject to the widest variation, although
in the majority of cases recovery from the constitutional disturbances is
complete in two or three days, and in many cases in a few hours. Cases

in which illness is prolonged are septic in character and are rarely, if
ever, due to tne primary action of the venom. The most important
complications of snake bites are produced by the absorption of putrefactive
substances (sepsis) and by acute alcoholism, resulting from mistaken treat-
ment.

The bites of pigmy rattlers and massasaugas (Sistrurus) are prac-
tically never fatal to adults, except possibly through septic complications.
These small rettlers are our least poisonous snakes, for of 20 cases on
record, none ended fatally. Of 408 persons bitten by larger rattlesnakes
(Crotalus), 48 died; on the other hand, of 8 persons bitten by harlequin
snakes (Micrurus and Micruroides), 6 died. Of 97 cases of bites by the
copperhead (Agkistrodon mokasen), 5 ended fatally, and 9 persons out of 53
bitten by the cotton-mouth water moccasin (Agkistrodon viscivorus) died.
When death results from the bite of harlequin snakes (Micrurus and Micruroides),
it is usually between 18 and 24 hours after the bite. Symptoms of drowsi-
ness and general depression appear within an hour or so, but if the victim
survives three or four days, the danger of death passes away.

Bites on the head and trunk are more dangerous than elsewhere, and
the mortality rate for bites on the upper extremities is practically double
that for the lower. From 60 to 90 percent of the total number of cases
result from bites on feet or legs. The mortality in children under 10 years
of age bitten by our venomous snakes is at least double that of adults.

The number of deaths each year resulting from the bites of our
venomous snakes, however, indicates that these snakes are not so dangerous
a pest as has often been assumed. This does not mean that one should
needlessly take chances of being bitten by a rattlesnake, for the bite,
when not fatal, is followed by exceedingly painful symptoms and often im-
pairment of the part bitten. Young rattlesnakes only five or six inches
long are -capable of injecting venom in quantities sufficient to require
treatment.

In the majority of the reported cases of persons bitten by venomous
snakes, the victim was bitten on the foot or leg, indicating that a high
degree of protection can be obtained vy wearing high-topped shoes or heavy
leggings. Quail hunters in the swamps and prairies of the South will find
that the best protection is afforded by a pair of waist-high rubber wading
boots with special inserted canvas shank. In most cases a pair of leather
puttees worn over the leather shoes will give the necessary protection
against snake bites.

SNAKES COMMITTING SUICIDs

It has been stated, and substantiated. in at least one instance, that
rattlesnakes are susceptible to their own ncison, and that death has ensued
from the effects of their self-inflicted wounds. There is a possibility,
however, that in such cases the fang may have punctured the spinal cord or
some vital organ, and that death, therefore, is not invariably due to the
poison. Snekes are not lixely to bite themselves except when severely
injured or xheninfuriated and unable to wreak vengeance on the tormentor.
That rattlesnakes may be killed by the bites of other noisonous species of
snakes has been demonstrated oy experiment with captive specimens.

TREATMENT FOR BITES OF NORTH AMSRICAN POISONOUS SNAK#S

The following is a combination of recommendations from publications
by Drs. R. H. Hutchison and Dudley Jackson (see bibliography):

The chief precaution in case of snake bites is to prevent systemic
absorption of 2 fatal dose of venom from the quantity contained in the
tissues immediately surrounding the wound. To accomplish this, action
must be promot. Local treatment is of gre-test importance, and in addition
the patient should be kept as quiet ~s possible.

¢

Don'ts for the Victim

Don't run or get overhented. Don't take any alcoholic stimulants.
Circulation, incressed by exercise or by alcohol, serves to distribute the
poison much more ravidly through the body. Don't injure the tissues by
injecting potassium permanganate, which is now known to be of no value as
an antidote. Do not depend woon reputed snake-—bite "cures" commonly used.
Do not cauterize tne ares around the bite with burning gunpowder, strong
acids, or in any other way.

What to Do First

Apply a ligature, or tourniquet, a few inches above the dite. For
this purpose use a rubber garter, a piece of small rubber tubing, a hand-
kerchiefr, cord, or even a shoestring, which can be tightened by inserting
a stick and twisting. Do not bind the limb too tigntly, but just enough to
retard circulntion retarning through the veins toward the henrt. The sole
object of the tourniquet is to delay absorption of the poison into the
general circulation, but if it is applied too tightly or kept on too long,
gangrene is likely to set in, with resulting destruction of the flesh in
the affected nrea. It is important, therefore, to release the tourniquet
every 1O or 15 minutes for about a minute at a time.

Other First-~-aid Measures

Make a cross-cut incision at each fang mark. For this purpose use
a sharp clean kmife or razor blade and make the cut all the wey through the
Sicha, that is, about 1/4 inch deep and Ty/2 inch long, preferably connecting
the fang marks. Suction should then be applied to the affected spot for at
least half an hour, and the more blood and lymph that cen be extracted the

= tie

better. If a specicl suction bulb having more power than a breast pump

and with a smaller mouthpiece can be obtained, it will be found highly
efficient. In the absence of any such device, one may remove enough of

the venom by suction with the mouth. It is best to be sure that there is
no abrasion in the mouth, for the venom is effective wherever it may enter
the blood stream. The principal thing to do is to use suction and remove
as mach of the venom and as quickly as possible. If the above procedure
is followed within one hour after the bite, the chences are that no further
treatment will be necessnry. It is always best, of course, to seek the
care of a competent physician as quickly as possible.

While the cutting advised should go through the skin, care should
be taken not to cut too deeply nor to sever blood vessels of any size. If
inadvertently this is done, bleeding from veins, recognized by the dark red
color and steady flow, may be checked by a tourniquet placed on the far
side of the cut from the heart. Bleeding from an artery is bright red and
in spurts and may be controlled by placing the tourniquet between the wound
and the heart. In either case a knot in the tourniquet or a solid object
under it should be placed directly over the severed blood vessel.

If you have antivenin with you, read carefully the directions for
preparing the syringe and making the injection. Do not allow fear or
agitation to make you overlook important points. When the syringe has been
made ready, proceed at once to inject the entire contents of the syringe
under the skin near the bite. The tourniquet should then be released for
a minute.

Additional Treatment

Additional treatment, or treatment in cases where the above methods
were not used soon after the bite, preferably to be administered by a surgeon,
should consist of following up the advance of the swollen area and making
a double row of incisions at the very upper edges of the swollen parts.

These should be about 1/8 by 1/8 inch, and a series of them should completely
encircle the limb affected.

It is well to remark here that novocain can be used by even a lay-
man witnout ill effect. Besides enabling the one operating to do the
cutting without pain to the patient, it also serves somewhat to check the
spread of the venom. It may be injected completely around the limb and
is very valuable in any emergency where a considerable amount of pain is
unavoidable in. rendering first aid.

As the swelling advances the one administering medical aid should
follow it up with the incisions, and should apply suction for a period of
at least thirty minutes to every series of incisions. In case one
particular region becomes more swollen than the others - a nest of incisions
should be made over and around it and suction applied there. If improvement
is not shown the incision treatment should be repeated every four hours and
the suction kept up constantly, until relief is obtained. The punctures
will continue to leak diluted venom and bloody lymph for several hours.
The real danger lies in making an insufficient number of incisions rather
than too many. Should there te any doubt as to the number made, one should

my dere

double the amount rather than be content. with the minimum.

It is most highly advised to keep the bowels of the patient Open and
free, using an irrigation of salt and soda solution if necessary.

aS ee

If the victim has not received an injection of antiverlin, it is”
important to inject the contents of one syringe as soon as possible. At
the same time, release the tourniquet, if one has been applied.

Repeat the injections every one or two hours unless and until
symptoms are markedly diminished. To hasten.the absorption of the serum,
intramuscular injections are advised, and, in severe cases and those seen
late, intravenous injection is recommended. In small children, when intra-
venous injection is difficult, the antivenin may te given intraperitoneallye
In shocked cases, physiological salt solution injected intravenously and.
blood transfusion are supplementary measures of life-saving value. For
weak pulse and threatened heart failure, give caffeine or strycnnine.

If incisions have been made at the site of the bite, the wounds
should be irrigated with a 1 or 2 percent salt solution (not normal saline).
The application of strong suction may be continued over these incisions,
if the symptoms and condition of the patient indicate the necessity of
pushing the treatment. Otherwise, apply a hot application of a 1:10,000
part solution of mercury bichloride or a strong magnesium sulphate solution.

Bxtra Precautions

It sometimes happens tneat after the first shock and reaction have
passed, the patient will show marked improvement. Some fatalities from
snake bite are plainly ceused by an undue sense of security following the
observation that most patients do well for the first 15 hours. Even though
the general symotoms may be mild, it is important to keep the patient under
close observation for at least 24 hours, and active treatment should be
continued as long as the swelling is progressing, Repeat the injections
of antivenin every 1 or 2 hours if the swelling is increasing. The danger
is always in under-treatment rather than in over-treatment.

In treatment of snake-bite in children it is important to double
the initial adult dosage. The reason for this is that a mathematical rela-
tion exists between the weight of the body and the amount of venom that it
can normally neutralize and dispose of without serious injury, although
the amount injected by the snake is approximately the seme. The smaller
and lighter the body of the victim, the less venom it can withstand, and
the greater the excess of venom over the normal body resistance. Therefore,
if the victim is a young child, there is much more venom requiring
neutralization by the serum.

RATTLES

According to popular superstition a rattlesnake acquires a new ring
on the rattle each year, and hence the number of rings composing the rattle

is supposed to indicate the age of the reptile. This notion is wholly in-
correct, for the rattlesnake adds from two to four rings each year, usually,
three. Under normal conditions one ring is added each time the snake sheds
its skin. The young rattler is provided with a single button at birth,

and within a few days it sheds its skin and commences feeding; in about

two months it sheds its skin for the second time and then the first ring
of the rattle is uncovered or added. This has been growing under the old
skin, and its presence was apvarent in the swollen appearance of the tail
at the base of the original button. The last seven or eizht vertebrae
fuse together shortly after birth and form a composite bone known as the
"shaker!, and it is around this bone that each cap or ring of the ratile
forms.

All our snakes shed their skin one or more times during the year.
The shed skin usually comes off entire, so that from head to tail it forms
but a single piece of very thin transparent materisl, and is generally
turned inside out. That part of \the skin that covers the cap on the rattle—
snake's tail cannot be shed on account of its peculiar shape. At the time
the skin is shed, however, it is loosened ond dislodged from its place and
moves backward to become an adéitional ring on the rattle. Thus the rattle
of the rattlesnake is simply a series of shed caps or rings, heid together
mechanically and loosely because of their shape. The rattle seldom numbers
more than ten rings because the vibration at the tin is so great that the
terminal rings are soon worn down or broken off.

It has often been asserted that nature equipped the rattlesnake with
this rattle to warn enemies away from its death-denling fangs, but it is
the opinion of many naturalists that the rattle is used as a call during
the breeding seasone The idea that the rattlesnake cannot rattle when its
rattles are wet from swimming or being in wet grass or rainstorms. is in-
correct.

YOUNG

Barly in the fall the female rattlesnake brings forth 6 to 9 young
about 5 inches long, the eggs having been retained in her body until
‘hatched. The young display all the traits of the adults, and will try to

rattle and bite as soon as they are born.

The copperhead and the water moccasin give birth to young during
July, the litters averaging from 7 to 9.

Unlike the pit vipers, the harlequin snake is oviparous, and deposits
its eggs late in May or early in Jume in decaying bark or damp soil. As
many as 7 eggs have been found together.

EXPOSURE TO SUN

The popular belief that rattlesnakes will die upon being exposed to
strong sunlight for ten minutes has recently been partially confirmed by
scientific experiment. The death of the snake is due not so much to the
effect of the sun's rays as to the combination of solar heat and radiation
from the rocks or sand on which the snake is lying, frequently raising the
air temperature to a very high point. Such excessive temperatures quickly
raise the temperatures of cold-blooded snakes even beyond the apparent
maximum of 46° C. which they can tolerate.

Bo AW ee

FOOD HABITS

xamination of all accessible accounts of the food habits of the
poisonous snakes indicates that rattlesnakes feed on any sort of smalzer
vertebrates that may come within their reach. The following items have been
found upon examination of stomachs: Grounc squirrels, chipmunks, pocxet
gophers, young prairie dogs, kangaroo rats, deer mice, meacow mice, and
ecottontail rabbits; various small lizards, such as Uta, Cnemidophorus, and

La)

Gerrhonotus; frogs and toads; and occasionally birds as large as quail.

The food habits of the copperhead and cotton-mouth water moccasin,
judging from published accounts, are essentially like those of the rattle-
snake, except that more aquatic vertebrates, such as turtles and round-
tailed water’rats, are available for the water. maccasin.

The harlequin snake does most of its feeding at night, capturing small
snakes and lizards, particulerly skinks (Humeces).

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