Chapter XIII: Snakes in Relation to Man (1)

Under this head, the question of poisonous snakes naturally occupies the first place. In addition to what has been said above in Chapter VI., dealing with the anatomical and physiological aspects of the subject, we have to allude to the accidents caused by these dangerous reptiles, and the measures taken to combat them.

The enormous mortality for which snake-bite is responsible in India is well known. Statistics establish the fact that an average of 20,000 human lives are thus lost annually: 24,264 is the official return for 1911. In Australia, where highly poisonous snakes of various genera and species abound, the fatal cases are likewise very numerous, though less in proportion than in South America, and no doubt also in Africa. In the small island of Martinique, the Fer-de-Lance, _Lachesis lanceolatus_, causes every year the death of about 100 human creatures. Though numerous in species, the poisonous snakes of Ceylon cause a comparatively small mortality--200 per annum.

Modern research has resulted in the discovery of the only effective antidote for snake-venom intoxication: the serotherapic treatment. An animal that has been treated over a length of time with the venom of a poisonous snake, such as a Cobra, yields a serum which is antitoxic towards that venom; but the great difficulty resides in the specificity of the different poisons, which often renders the use of the serum ineffective in countries like India and Australia, where several kinds of poisonous snakes occur in the same district (see above, p. 67). In India, where a special laboratory has been established for the supply of antivenine, at the Central Institute of Kasauli, it has been found impossible to obtain any venoms but those of the Cobra and Russell's Viper in sufficient quantity to immunize animals, and thus produce the serum necessary for dealing with the bite of the King Cobra, the Krait, and the Echis Viper.

In Pondicherry the French Government places annually a sum of 200 rupees at the disposal of the director of the hospital for obtaining Cobra poison, the snakes, to be brought alive, being paid for to the natives at the rate of half a rupee to one rupee each, according to size and condition. Six hundred and fifty-three specimens were thus purchased in less than two years (1901-1903). The poison is utilized for the preparation of Calmette's antivenine, which, as we have said above, is only effective against cobra poison, and, unfortunately, useless for the cure of bites from other species.

In Brazil, where the number of accidents is estimated at 19,200 per annum, and that of fatal cases at 4,800, over 2,000 snakes (_Lachesis_ and _Crotalus_) are brought annually to the Serotherapic Institute of Batantan, in the province of S. Paolo, for the preparation of the antitoxic serum, which is given in exchange for the snakes. According to the latest report of the Institute (1911), two serums are distributed: the anti-crotaline (for Rattlesnake bite) and the anti-bothropine (for Lachesis bite); the third, the anti-elapine (for Coral-snake bite), is in course of preparation.

In many countries a premium has for years been paid for the heads of poisonous snakes, and has led to the destruction of enormous numbers of them, without, however, resulting in a very appreciable diminution of the dangerous reptiles. More than £12,000 has been spent for this purpose in India alone; the numbers destroyed in 1885 and 1886 throughout British India amount to 420,044 and 417,596 respectively. About forty years ago the Governor of St. Lucia offered a reward of 4d. for every Fer-de-Lance's head. But the negroes caught them alive and bred families of snakes for the sake of the reward, and thereby made what was for them a little fortune, these snakes bringing forth up to sixty young at a birth. The reward had to be abolished very soon.

Now about the Vipers of Europe, the only really dangerous snakes of this part of the world.

Although the Adder, _Vipera berus_, is quite common in many parts of England and Scotland, accidents caused by its bite are rarely heard of, and cases of death are few and far between. It is not so, however, on the Continent, where the same species, and especially its close ally, the more southern _V. aspis_, are responsible for many fatalities, due no doubt to the more virulent action of the venom in a warmer climate.

In the French Departments Loire-Inférieure and Vendée, where these snakes are very plentiful, three or four cases of death are reported annually. From 1860 to 1868, 370 serious accidents to man have been carefully recorded, 53 ending in death, not only in the case of children, but also of adults of all ages, in 10 cases within one to twenty-four hours. In the Puy-de-Dôme cases of death are of frequent occurrence. In Germany and in Switzerland, 12 or 13 per cent. of the cases on record have ended fatally. Instances of death from the bite of the south-eastern _V. ammodytes_ are also not infrequent. On the other hand, the bite of _V. ursinii_, which is but seldom inflicted, is not known to have ever resulted in death.

It must be borne in mind that accidents are much more frequent in districts where the poorer classes are in the habit of going about barefoot.

Anyhow, it is certain that Vipers are a serious danger in many parts of Europe, not only to man, but also to horses, cattle, and dogs. And it is not surprising that efforts have been made to reduce their numbers. The most efficacious means, besides the protection of certain animals and birds which feed on Vipers, appeared to be the institution of premiums to be paid for the heads of the dangerous snakes. By offering 2-1/2d. per head, 500,000 Vipers (_V. aspis_) were destroyed from 1864 to 1890 in three French departments, Haute-Saône, Doubs, and Jura, and in one district (Chaumont) of the Haute-Marne 57,045 were killed from 1856 to 1861; this gives an idea of the extraordinary abundance of these snakes in some parts of France. In the Puy-de-Dôme the premium was fixed for a time at 5d., and one man managed to destroy in the course of seven years 9,175 Vipers (_V. berus_ and _V. aspis_). A woman in the Deux-Sèvres has made a living for many years by catching Vipers, the heads of which were paid to her at the rate of 5d. each. The average number of her captures amounted to 2,062 per annum (mostly _V. aspis_). Around Oesnitz in Saxony, 2,140 _V. berus_ were killed in 1889, and 3,335 in 1890. In a single district in Southern Styria the heads of 4,197 _V. berus_ and 7,381 _V. ammodytes_ were sent in for the reward in the course of two years (1892, 1893).

In spite of all this effort, the institution of the bounty has not answered expectations, and, with the exception of a few districts, Vipers remain as plentiful as ever, showing what little man can do in altering the equilibrium of Nature, except by interfering with the natural conditions under which animals live. Cultivation of the ground or destruction by fire of the vegetation of the wilderness seems to be the only efficacious means of getting rid of so abundant and prolific a creature as the Viper.

A word may be said, however, in defence of Vipers: they do a great deal of good to agriculture by the destruction of small rodents, on which they feed chiefly, and whose multiplication they serve to keep in check. It must be pointed out that, with the exception of the species of _Coluber_ and _Zamenis_, other European snakes are to be regarded as indirectly injurious to agriculture, feeding as they do mainly on lizards or frogs and toads, which, as insectivores, deserve to be protected.

Snakes are not of much economic value to man. Tanned skins of Boas and Pythons are utilized for making shoes and fancy articles, such as purses, pocket-books, blotters, etc., and the Siamese make the drum-heads of native drums out of the skins of Pythons and _Acrochordus_. To say nothing of savages, who seem to be partial to the flesh of large snakes, the peasantry in some parts of France do not disdain snakes as an article of food, the Grass-snake being occasionally served in village inns under the name of _Anguilles de haies_, or hedge-eels.

Viper fat has for a long time been in request as an ointment in the case of various affections, and much used by quack doctors in the preparation of their remedies. Some forty years ago a chemist in Challans (Vendée) collected Vipers (_V. aspis_) for medicinal purposes, and was able to send several thousands to Paris in the course of a few years, thus realizing a considerable sum of money, but the demand has gradually fallen off since.

Very frequent in the past, snake-worship is still prevalent in many parts of India, where the Cobra is held in great veneration, and is never willingly killed by the Hindoo. In pre-Buddhist days the gods were represented with a canopy of five or seven Cobras over them. The North African Cobra was sacred to the ancient Egyptians, and is profusely represented on the monuments and tombs; it was also an emblem of the physical sun, and, as a sign of royal power, along with the sun's disc, formed part of the headdress of all solar deities. The Greeks and Romans also worshipped snakes, and the god of medicine is represented holding a snake, which is supposed to be _Coluber longissimus_, the so-called "Æsculapian snake"; the occurrence at the present day of certain common Italian species (_Zamenis gemonensis_, _Coluber longissimus_, _Tropidonotus tessellatus_) in isolated localities of Central Europe, formerly Roman settlements, has been attributed to their importation for use in the temples.

Snake-charmers have existed from the remotest antiquity, and are still to be found among all races of men, from the accomplished Indian juggler down to the more commonplace European snake-catcher, who boasts of his immunity, and of his art of attracting snakes by devices of which he has the secret. The Libyan Psillii of the ancient Romans have handed down their art to the present day, and their performances are to be witnessed in most of the towns of Egypt and Tunisia. But India above all lands is reputed for its snake-charmers, and the favourite species used by them is the Cobra, which, by the way in which it raises the anterior part of the body and expands the region behind the head, lends itself better than any other to the display. Constantly facing the man before him, and swaying the raised anterior part of the body, it seems to dance to the music performed by the snake-man, people believing it to be charmed by the sounds of the instrument. However, anyone sitting on the ground in front of a Cobra, and swaying the body from side to side as does the man, can obtain the same result without the aid of any sort of music.

The most puzzling thing about these performances is how the man can thus play with impunity with so deadly a snake. It is a mistake to think that the snake is rendered harmless through the poison fangs having been extracted, although this subterfuge is frequently resorted to by the less accomplished jugglers. The immunity of the snake-charmer is to be explained by the fact that the man has submitted himself to a series of successive and graduated inoculations of the venom, a process similar to vaccination, which renders his blood proof against the venom of the particular species of snake, and that one only, used for his performances.

Another deadly snake shown by the snake-charmers in North Africa is the Horned Viper, _Cerastes cornutus_. The presence of an erect spike above the eye is, however, not a constant character in this snake, and hornless specimens are made to look more formidable by spines of the hedgehog being inserted in the proper place; the illusion is such that even naturalists have been deceived by this trick.

Indian snake-charmers profess to have a belief in the efficacy of snake-stones, or bezoar stones, as a remedy to be applied on the part bitten by a poisonous snake, a belief shared by the natives of many tropical countries. These stones, extracted from various reptiles, birds, and mammals, are calcareous concretions from the stomach or bladder, sometimes composed of superphosphate of lime, sometimes of phosphate of ammonia or magnesia. The value of a bezoar stone being supposed to increase with its size, the larger are sold in India at very high prices.

In many places a popular belief prevails that such stones are found in the heads of snakes. Mr. J. A. Bucknill, now Attorney-General at Hong-Kong, who spent five years in Cyprus, has informed the author that the Viper of the latter island, _Vipera lebetina_, is commonly believed to contain a stone which, when applied to the bite of a poisonous snake, quickly nullifies the effect; it is also believed that, when this stone is allowed to stand in a glass of water and the water is drunk, it endows the drinker with surprising virility. Indeed, there was an action tried by the English judge at Larnaka in which the plaintiff claimed the return, or damages for the non-return, of one of these "Viper-stones" which he had lent for a monetary consideration to the defendant for the promotion of his manly vigour, and Mr. Bucknill's recollection is that the plaintiff recovered £10 for the loss.

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SYSTEMATIC ACCOUNT OF THE SNAKES OF EUROPE[A]

FIRST FAMILY: TYPHLOPIDÆ

Skull compact, with short, toothless lower jaw, without transverse bone; palatine and pterygoid reduced and toothless; maxillary small, loosely attached to lower surface of cranium and bearing a few small teeth; no supratemporal, the quadrate articulated to the proötic; a coronoid element in the lower jaw. Rudiments of a pelvic arch, reduced to a single bone. Body vermiform, covered with uniform cycloid scales; head small, not distinct from the body; mouth small, crescentic, inferior; eyes under the more or less transparent head-shields, sometimes entirely hidden. Worm-like, smooth, shiny snakes, of small or very small size, the largest measuring little over 2 feet, of subterranean habits, or found in rotten trees, under stones, or in the saw-dust of sawmills; rarely appearing on the surface except when the ground is soaked by heavy rains.

Inhabit the intertropical parts of the whole world, as well as South Africa, Southern Asia, and Southern Australia. One species occurs in South-Eastern Europe. About 120 species are known.

GENUS TYPHLOPS, SCHNEIDER

Head with large shields; nostril in a single or divided nasal. Tail extremely short.

1. TYPHLOPS VERMICULARIS, Merrem
The Greek Blind-Snake

_Form._--Slender, worm-like, the greatest diameter of the body 40 to 52 times in the total length. Tail about as long as broad, ending in a short spine. Snout depressed, rounded, strongly projecting. Eyes distinguishable, appearing as a small black spot surrounded by an unpigmented circle; nostrils lateral.

_Head-Shields._--Rostral about one-third, or a little less than one-third, the width of the head, extending on its upper surface nearly to the level of the eyes. Nasal incompletely divided, the cleft proceeding from the second labial. Preocular present, about as broad as the ocular, in contact with the second and third labials. Upper head-scales feebly enlarged and subequal. Four upper labials.

_PLATE I_

_After Sordelli_]

_After Sordelli_]

_Scales._--Equal, 22 or 24 round the body.

_Coloration._--Brown or yellowish-brown above, yellowish beneath.

_Total Length._--10 inches. A specimen from Cyprus is reported to measure 14 inches.

_Distribution._--This species has long been known from Greece, the Ionian Islands, and the Grecian Archipelago. It is on record from the Eli-Deren Pass, in Bulgaria. A specimen stated to come from Constantinople is preserved in the British Museum. The range further extends over a considerable part of South-Western Asia, viz., Asia Minor, Syria, Cyprus, Transcaucasia, Persia, Turkestan, and Afghanistan.

_Habits._--Pretty alert in its movements, this little snake has considerable constricting powers, and coils itself fast round the fingers when handled. It lives much after the manner of earth-worms, and if dug out of loam or sand a specimen must be instantly grasped, as it draws back with extraordinary quickness. Its food probably consists mainly of earthworms and small insects. Some exotic species of the genus are known to feed on termites, and are often dug out of their nests.

_Reproduction._--No observations have been made that I am aware of, but, as some of the exotic species of which we know something more lay large, elongate eggs, it is probable that this species also is oviparous.

SECOND FAMILY: BOIDÆ

Maxillary, palatine, and pterygoid bones movable; transverse bone present; pterygoid extending to quadrate or mandible; supratemporal present, attached scale-like to cranium, suspending quadrate; prefrontal in contact with nasal; a coronoid element in the lower jaw. Teeth in both jaws. Vestiges of pelvis and hind limbs, usually terminating, at least in males, in a claw-like horny spur on each side of the vent.

This family contains, besides the gigantic Boas and Pythons, several small more or less burrowing forms, among which the genus _Eryx_, its only European representative, belonging to the subfamily Boinæ, characterized by the absence of a supratemporal bone and of premaxillary teeth. This subfamily, the largest members of which inhabit tropical America, is distributed over the hotter parts of America, Asia west of the Bay of Bengal, Madagascar, the Mascarene Islands, Africa north of the equator, Papuasia, and some islands of the South Pacific. The habitat of the European species is confined to the eastern and southern countries of the Mediterranean district.

This very varied family, including terrestrial, arboreal, aquatic, and burrowing forms, is a comparatively small one as regards the number of species, viz., about sixty, of which one-third pertain to the Pythoninæ, which inhabit tropical and South Africa, Southern Asia, Papuasia, Australia, and Mexico.

GENUS ERYX, DAUDIN

Anterior maxillary and mandibular teeth longer than the posterior. Head small, not distinct from neck, covered with small scales; a large rostral shield. Eye very small, with vertical pupil. Body cylindrical; scales small; ventral shields narrow. Tail very short; subcaudal shields mostly single.

The range of this genus, embracing eight species, extends from South-Eastern Europe and Africa north of the equator to Central Asia and India.

2. ERYX JACULUS, Linnæus
The Javelin Sand-Boa

_Form._--Stout. Head small, not distinct from neck; snout projecting beyond the mouth; eye directed upwards and outwards; a feeble mental groove. Tail, ending very obtusely, one-tenth to one-sixteenth of the total length. Anal spurs more or less developed, often absent in the female.

_Head-Shields._--Rostral very large and broad, with angular horizontal edge, followed by a pair of internasals and a second row of two or three small shields, the rest of the upper surface of the head covered with scale-like shields, 5 to 8 from eye to eye across the vertex, 7 to 11 round the eye; 9 to 12 upper labials, second or third deepest, separated from the eye by one or two series of scales. Nostril between the internasal and two nasals, the anterior of which sometimes fuses with the former. Two or three series of scales between the nasals and the eye.

_Scales._--Smooth, feebly keeled on the posterior part of the body and on the tail, in 40 to 51 rows. Ventrals narrow, occupying about one-third of the ventral surface, 163 to 200; anal small, entire; subcaudals all or greater part single, 15 to 29.

_Coloration._--Pale greyish, reddish, or yellowish-brown above, with brown, purplish-brown, or blackish markings, which may be very irregular or form a single or alternating series of large blotches or cross-bands on the back; the sides with smaller spots; these markings may be confluent and so large as to reduce the ground colour to small yellowish spots; one, two, or three short, dark stripes often present on the nape; a dark streak from the eye to the angle of the mouth; sometimes a dark curved band from eye to eye across the upper surface of the snout. Lower parts yellowish-white, uniform or with small blackish spots.

_Size._--2-1/4 feet is the greatest length which this snake is known to attain.

_Distribution._--Originally described from Lower Egypt, and extending westwards to Algeria, this _Eryx_ has been found in Greece, in Corfu, in the Cyclades, in Turkey, and in Roumania. It occurs also in Asia Minor, in Transcaucasia, in Transcaspia, in Northern Persia, and in Syria. It has been found at an altitude of 5,000 feet in Persia, to the west of Lake Urmia. A closely allied form (_E. miliaris_, Pallas), which has been confounded with this species, extends from Transcaspia to Turkestan and Afghanistan.

The reported occurrence of this snake in Bulgaria is based on a specimen labelled "Bulgaria (?)" in the Sofia University Museum. The species is omitted from Kovatscheff's latest list of Bulgarian Reptiles.

_Habits._--This diminutive Boid is a burrower in arid, sandy districts, appearing only early in the morning or towards dusk; it is as a rule more crepuscular than nocturnal. Notwithstanding its rather heavy form, it is capable of very quick movements, darting like an arrow upon its prey, which consists chiefly of small mammals and lizards. A constrictor, like all the members of the family to which it pertains, it crushes its prey before swallowing it. If given several mice at a time, it will catch and kill them all in succession before proceeding to feed. Specimens recently discovered in the Danube Valley in Roumania were found to live in the sand at the bottom of small limestone caves, going about at night and feeding principally on slugs. Unlike other snakes, it is said to lap dewdrops with its tongue. It is a gentle snake, seldom attempting to bite.

Egyptian jugglers are in the habit of implanting the claw of a bird or small mammal in the skin of the head of this snake, above each eye, in order to give it a more formidable appearance.

_Reproduction._--Like the other species of _Eryx_, this snake is ovoviviparous, but, beyond this fact, nothing appears to have been observed concerning the breeding habits, although many examples have been kept in captivity.

THIRD FAMILY: COLUBRIDÆ

Maxillary, palatine, and pterygoid bones movable; transverse bone present; pterygoid extending to quadrate or mandible; supratemporal present, attached scale-like to cranium, suspending quadrate; prefrontal not in contact with nasal; maxillary horizontal, not movable perpendicularly to the transverse bone; no coronoid bone. Teeth in both jaws. No vestiges of pelvic arch.

An enormous group, comprising the great majority of snakes. Divided into three parallel series:

_A._ Aglypha, with all the teeth solid.

_B._ Opisthoglypha, with one or more of the posterior maxillary teeth grooved.

_C._ Proteroglypha, with the anterior maxillary teeth grooved or canaliculated.

The third, which is not represented in Europe, includes some of the most deadly snakes, such as the Cobras, Kraits, Death-adders, etc.

The European genera are thus distributed in the two other series:

AGLYPHA (COLUBRINÆ): _Tropidonotus_, _Zamenis_, _Coluber_, _Coronella_, _Contia_.

OPISTHOGLYPHA (DIPSADOMORPHINÆ): _Coelopeltis_, _Macroprotodon_, _Tarbophis_.

These genera give but a feeble idea of the variety of forms included in this family, which comprises adaptations to every mode of life for which snakes are fitted.

The distribution of the family coincides with that of the order, extending over the whole world with the exception of the Arctic and Antarctic regions, and Ireland and New Zealand, as well as most of the smaller islands of the Pacific Ocean.

GENUS TROPIDONOTUS, KUHL

Maxillary teeth increasing in size posteriorly. Head more or less distinct from neck; eye moderate or rather small, with round pupil. Body more or less elongate; scales keeled, with apical pits. Tail moderate.

This large genus, comprising about ninety species, and of almost cosmopolitan distribution, with the exception of South America and the greater part of Australia, may be divided into several subgenera, two of which are represented in Europe--_Tropidonotus_ proper, with the common _T. natrix_, and _Nerodia_, Baird and Girard, with two closely related species of more thoroughly aquatic habits, _T. tessellatus_ and _T. viperinus_.

3. TROPIDONOTUS NATRIX, Linnæus
(_Natrix vulgaris_, Laurenti; _Coluber torquatus_, Lacepède)
The Grass-Snake, or Ring-Snake

_Form._--Moderately slender; snout short, obtuse, not prominent; eyes and nostrils lateral, the former moderately large. Tail four to six and a half times in the total length.

_Head-Shields._--Rostral broader than deep, visible from above. Nasal divided, very rarely semidivided. Internasals at least as broad as long, trapezoid, shorter than the prefrontals. Frontal broader than the supraocular, once and one-third to once and a half as long as broad, as long as or a little shorter than its distance from the end of the snout, shorter than the parietals, not in contact with the preocular. Loreal deeper than long. One (rarely two) pre- and three (rarely two or four) postoculars. Temporals 1 + 2. Upper labials seven (rarely six or eight), third and fourth (or fourth and fifth) entering the eye. Four or five lower labials in contact with the anterior chin-shields, which are shorter than the posterior.

_Scales_ with two apical pits, in nineteen rows, strongly keeled on the body, of outer row smooth or faintly keeled. Ventral shields 157 to 181; anal divided; subcaudals 50 to 88.

_Coloration._--Very variable. We shall first describe the typical form, and then allude to the principal varieties and individual variations with which we are acquainted.

Grey, bluish-grey, olive, or brown, above, usually with black spots or narrow bars on the back, and vertical bars on the sides; upper lip whitish or yellowish, with the sutures between the shields black; the preocular, and sometimes the postoculars, yellow in the young; a white, yellow, or orange collar on the nape, sometimes uninterrupted, more often divided in the middle, bordered behind by two black subtriangular or crescentic blotches, which usually meet on the median line; the bright collar often becomes faint, or even entirely disappears, in large females (Plate II., first figure); belly usually checkered black and grey or white, more rarely grey with small black spots, or entirely black. Iris dark brown or reddish-brown, with a golden circle round the pupil. This is the form found in England and Central Europe and in some parts of Southern Europe.

In Jersey, in the Spanish Peninsula, and in Cyprus, the white or yellow collar, which is always present in the very young, soon disappears, and so does usually the black collar, which is either much reduced or entirely absent (var. _astreptophorus_, Seoane). Some large specimens from the Spanish Peninsula are uniform olive, without any markings.

Another variation (Plate II., third figure), rare in France, but common in Italy, South-Eastern Europe, and Asia Minor (var. _persa_, Pallas; _bilineatus_, Bibr.; _murorum_, Bonap.) has the collar well marked, though widely interrupted in the middle, and a white, yellow, or orange streak extends along each side of the back, which may bear the usual black markings in addition.

In some specimens from Austria and Corfu (var. _subfasciatus_, Werner) the belly is white, with black bars occupying the free edge of each ventral shield.

A very remarkable variety (var. _cettii_, Gené) from Corsica and Sardinia (Plate II., second figure) is grey or olive above, with the black markings confluent into more or less regular annuli, which are nearly as wide as the spaces between them; these annuli are often broken up on the middle line of the back, and alternating; the collar is absent, or is transformed into the first annulus, and the upper surface of the head is more or less spotted or blotched with black. This pattern is most distinct in young and half-grown specimens; in large examples the annuli may break up into spots, disposed with great symmetry in transverse series. The belly is black, spotted with white.

A specimen 20 inches long, from Bona, Algeria (Lataste collection), has the posterior half of the head, from between the eyes and behind the postocular shields, of an intense black, followed by the usual yellow and black collar; two light dots close together on the parietal shields.

Some specimens are entirely or nearly entirely black. In the var. _picturatus_, Jan, from the Caucasus, the upper parts are sprinkled all over with light dots, and the yellow collar is present; the belly is grey, dotted with black, and with white spots on the sides. In others the body is black above, and checkered black and white beneath (var. _scutatus_, Pall.), or entirely black (var. _ater_, Eichw.). This melanism never appears until the second or third year of life, the young being marked like the typical form.

Albinos have occasionally been met with, yellowish flesh-colour with reddish markings, and a white or yellow collar, the eye and the tongue red. Such an albino, from Horsted Keynes, Sussex, is preserved in the British Museum. A remarkable aberration, to be regarded as an imperfect albino, has been found in Dorsetshire, and described as uniform whitish, with a well-defined broad longitudinal central dorsal pale yellow-brown band.

_Size._--May reach a length of 6 feet 8 inches. Such giants, females, known from Sardinia, Sicily, and Istria, are, however, very exceptional, individuals of this species seldom exceeding a length of 4 feet. The largest British specimen on record, from Wales, is stated to measure 5 feet 10 inches. Males rarely exceed 3 feet.

_Monstrosity._--A dicephalous young, with the two well-formed heads side by side, is preserved in the British Museum, and several others have been described, one being reported to have lived for about a month.

_PLATE II_

_After Sordelli_]

_After Sordelli_]

_Distribution._--_Tropidonotus natrix_ occurs all over Europe, with, of course, the exception of Ireland, as far north as the extreme south-east of Scotland, and the sixty-fifth degree in Scandinavia and Finland, and as high up as 7,450 feet in the Italian Alps. With the exception of a few districts in England and in Central Europe, as well as in the extreme north, it is common everywhere, in the north as well as in the south. On the Mediterranean islands it is absent from the Baleares and Malta. In North Africa it is known from Algeria and Tunisia, north of the Atlas, where it does not seem, however, to be at all common. It has a wide range in Asia, extending eastwards to Lake Baikal, and southwards to Cyprus, Asia Minor, and Northern Persia. In the south-east of its range, the bilineated variety predominates over the typical form. The melanistic so-called varieties are not geographically restricted, but occur all over the habitat of the species, though not recorded from England.

_Habits._--Although fond of water, and often seen swimming in ponds or streams or creeping by the water's edge, this snake is far less aquatic than its two congeners described hereafter; it often occurs on dry chalk hills or in woods far from any water. It is moderately agile in its movements, and easily caught, on which occasions it hisses loudly and emits a nauseous smell from its anal glands, together with the renal dejections, but makes no attempt to bite; exceptionally an individual may go so far as to strike with open mouth, but cases of this snake really biting are extremely rare. However, Gené says of the male of his _Natrix cettii_, "iracundum et mordacissimum animal." Dr. Gadow relates his experience with aggressive specimens which inhabited a swamp with a little stream to the north of Oporto, close to the coast. To his utter surprise, some of them actually made for him, swimming along rapidly with the head erect, about 6 inches above the water, and darting forwards with widely opened jaws; but they did not bite. According to Professor Kathariner, this snake when caught has been observed to sham death, lying rigid and motionless, with open gape. Some specimens do well in captivity, and are known to have lived for many years; others refuse all food and die of starvation. After a time they become tolerably tame, and cease to produce the offensive odour when handled.

The food consists of frogs and toads--the latter being preferred notwithstanding their poisonous secretion, which protects them from the attacks of most animals--occasionally of newts, seldom of fish; these snakes are reported to have a predilection for tree-frogs, and to feed occasionally on mice and birds, but most observers agree that they will not take anything higher in the zoological scale than frogs. The prey is swallowed alive, and, if not very large, four or five frogs or toads are often taken in succession; a case is known of a snake having swallowed twenty very small frogs at one meal. The young feed on worms and batrachian larvæ, in addition to very small frogs and toads.

The Grass-snake gets on very well with the Adder, to whose venom it is immune.

It has more than once been met with swimming in the sea, and a case is reported of one having been captured in the open sea twenty-five miles from the nearest land, no doubt carried away by the current, but still perfectly lively.

The hibernating season is spent in holes in walls or at the root of trees, often under manure-heaps, and the awakening occurs in March or April, soon to be followed by the first exuviation and the pairing.

_Reproduction._--Pairing takes place in April or in May, according to the climate, and the eggs are laid between June and August, the young emerging six to ten weeks later. It is probable that a second pairing occasionally takes place in the autumn, as eggs have sometimes been found in manure-heaps at the end of winter. Females do not breed until about 2 feet long, males a little sooner. The eggs number 11 to 48, according to the size of the female, and, after being produced in a string, stick together in a mass, without any regularity.

The eggs measure 1 to 1-1/2 inches in length, and when newly laid are about once and a half as long as broad. They often contain at the time they are produced a more or less developed embryo. They are sometimes laid in recesses in walls, in heaps of sawdust near sawmills, under dead leaves, but preferably in manure, for which purpose females often approach farms during the period of oviposition. Holes near baking ovens at the back of village houses are sometimes selected as breeding resorts. The female rolls herself up, and by violent contortions makes a sort of chamber in the manure, in which she may remain for some days after the eggs have been produced. It is not very unusual for several females to congregate for the purpose of laying, and as many as 1,200 eggs have been found in the same hole. The young on emerging has lost the umbilical cord, and measures 6 to 8-1/2 inches. It often remains for a considerable time, sometimes until the following spring, in the hole or manure-heap in which it was born, feeding principally on worms. Very young specimens are never found in the water.

4. TROPIDONOTUS TESSELLATUS, Laurenti
(_Coluber hydrus_, Pallas)
The Tessellated Water-Snake

_Form._--Rather slender; head rather long and narrow; snout obtuse, not prominent; eyes and nostrils directed upwards and outwards, the former rather small, the latter somewhat valvular. Tail four to six times in the total length.

_PLATE III_

_After Sordelli_]

_After Sordelli_]

_Head-Shields._--Rostral broader than deep, visible from above. Nasal often semidivided. Internasals usually as long as broad or longer, subtriangular, truncate in front, as long or nearly as long as the prefrontals. Frontal a little broader than the supraocular, once and a half to twice as long as broad, as long as or a little shorter than its distance from the end of the snout, shorter than the parietals, not in contact with the preocular. Loreal as deep as or deeper than long. Two (rarely one or three) preoculars, with or without a small subocular below; three postoculars, often with one or two suboculars below. Temporals 1 + 2. Upper labials eight (rarely seven, nine, or ten), fourth or fourth and fifth (rarely third or fifth) entering the eye. Five (rarely four) lower labials in contact with the anterior chin-shields, which are shorter than the posterior.

_Scales_ with two apical pits, in nineteen rows, strongly keeled, of outer row smooth or feebly keeled. Ventrals 160 to 187; anal divided; subcaudals 48 to 79.

_Coloration._--Olive, olive-grey, or brown above, with dark spots usually arranged quincuncially or forming narrow bars on the back (Plate III.); sides often with lighter vertical bars; a more or less distinct [V]-shaped dark band on the nape, sometimes produced as a median streak to the frontal shield; upper lip yellowish, with dark bars on the sutures between the shields. Lower parts whitish, yellow, orange, or red, marbled or checkered with black, or nearly entirely black. Iris golden, bronzy, or coppery red.

Some specimens depart very strikingly from the coloration thus briefly defined. We will now mention the principal variations which have been described: Sides of body checkered with black and yellow or black and red (var. _rubro-maculosus_, Dürigen). With four dark stripes along the anterior part of the back (var. _lineaticollis_, Werner). Above with four light streaks in addition to the dark markings. Uniform grey or light brown above (var. _concolor_, Jan, _hagenbecki_, Werner). Uniform black or blackish (var. _nigrescens_, De Betta). The most remarkable variety is the var. _vosseleri_, Werner, from Asia Minor: above with small black and yellowish spots, beneath yellowish with three blackish stripes beginning at some distance from the head, the median much weaker than the outer; the scales are less strongly keeled than in the typical form. There are also specimens with two very regular black stripes along the belly.

A case of chlorochroism, in a specimen from Dalmatia, has been observed by Peracca. The snake was sulphur yellow with black markings; a black band along the belly; iris golden.

An imperfect albino, which has been met with several times in Dalmatia, has been described as var. _flavescens_, Werner. Yellowish-white or brownish-yellow above, with small blackish spots; belly whitish in the middle, with a series of black spots, bright yellow on the sides; eye and tongue red.

_Size._--This snake occasionally reaches a length of 4 feet, but specimens over 3 feet are rare. The largest specimen in the British Museum measures 3 feet 10 inches.

_Distribution._--The Tessellated Snake has a wide range in Europe and Asia. It is found south of the Alps, from Liguria to Naples, and eastwards, extending northwards over the greater part of Austria-Hungary, and even as far as Saxony, and again reappears to the west in various localities of the Middle Rhine district (from Bingen to Coblenz and Kreuznach, from Nassau to Lahnstein) and of the Moselle. From Southern Russia it extends into Siberia as far as the Altai, the extreme west of China, and the extreme north-west of India; it is also found in Asia Minor, Transcaucasia, Persia, Mesopotamia, Syria, and the neighbouring parts of Egypt. Italy and the Rhine constitute the western limit of its range in Europe. It does not ascend to any considerable altitude in the mountains of Europe, but it is on record from 6,000 feet elevation in Chitral.

_Habits._--This is a far more aquatic species than the preceding, being seldom found in summer away from the water, in which it swims and dives to perfection; which does not prevent it from being equally agile on land. In accordance with these thoroughly aquatic habits, it feeds mostly on fish, although occasionally taking frogs and toads and their tadpoles. Small fish are swallowed in the water, but large ones are landed. This snake does not object to salt water, and it has been observed on the seashore near Odessa, chasing small fish, mostly gobies, in shallow water. Hibernation and pairing take place on land, and it is not until the latter function is accomplished that the snakes of this species resort to the water, which the females leave again for oviposition. Like the Grass-snake, the Tessellated Snake seldom bites.

_Reproduction._--Pairing takes place in spring, when large numbers have been observed to congregate for the purpose. As in the Viperine Snake, a second pairing may occur in the autumn, Dr. Werner having found a pair in copula on September 14, at Trebinje, Herzegovina, the female laying her eggs in the following July, which with the beginning of August is the time for oviposition. The eggs measure a little over an inch in length and two-thirds of an inch in width, and number 5 to 25; they are deposited under stones, in the fissures of walls and rocks, or under the refuse of tanneries.

5. TROPIDONOTUS VIPERINUS, Latreille
The Viperine Water-Snake

_Form._--Moderately slender; head shorter than in the preceding species; snout obtuse, not prominent; eyes and nostrils directed upwards and outwards, the former rather small, the latter somewhat valvular; tail four to six times in the total length.

_Head-Shields._--Rostral broader than deep, visible from above. Nasal usually semi-divided. Internasals as long as broad or longer, subtriangular, truncate in front, as long as the prefrontals. Frontal usually broader than the supraocular, once and a half to twice as long as broad, as long as or slightly longer than its distance from the end of the snout, shorter than the parietals, not in contact with the preocular. Loreal as deep as or a little deeper than long. One or two preoculars and two (rarely three) postoculars. Temporals 1 + 2 or 1 + 3. Upper labials seven (rarely eight), third and fourth (or third, fourth, or fourth and fifth) entering the eye. Four (rarely five) lower labials in contact with the anterior chin-shields, which are usually shorter than the posterior.

_Scales_ with two apical pits, in twenty-one (rarely nineteen or twenty-three) rows, strongly keeled, of outer row smooth or feebly keeled. Ventrals 147 to 164; anal divided; subcaudals 46 to 72.

_Coloration._--Grey, brown, or reddish above with two alternating series of dark brown or black spots on the back, or with a black zigzag dorsal band (Plate III., second figure), rarely with a single series of black vertebral spots; a lateral series of black spots, usually ocellar, with yellow centres; upper surface of head with dark symmetrical markings; a more or less distinct dark band on the temple, and another on each side of the nape, often edged with yellow in front; upper lip yellow, with dark bars on the sutures between the shields, or dark with a yellow spot on each shield. Lower parts yellow or red, checkered with black, or entirely black; the black of the belly may be connected with the ocellar lateral spots by black vertical bars. Iris golden, often mixed with brown.

A specimen from Ponte Carrega, near Genoa, preserved in the Genoa Museum, is remarkable as being of a dark olive-grey, with three series of black and yellow ocellar spots. It is further exceptional in having the scales in nineteen rows. A second specimen, from the same locality, with the normal number of scales, has some of the vertebral spots ocellar. Specimens with ocellar vertebral spots are found also in Sardinia and in Spain.

As in _T. natrix_, there occur, in the South of France, in Sardinia, in the Spanish Peninsula, and in North Africa, specimens with two light yellow or reddish lines along the back (Plate III., third figure), in addition to the usual markings (_C. aurolineatus_, Gervais, _T. chersoides_, Duméril and Bibron).

Melanism is rare in this species, only one specimen being known, from Nantes in Southern Brittany; uniform black, with the exception of a few white spots on the belly. A remarkable variety (var. _incertus_, Fatio), connecting this species with the preceding, occurs in Switzerland near Geneva. Not only is its coloration sometimes very similar to that of _T. tessellatus_, but it agrees with it in the scales being often disposed in nineteen rows instead of twenty-one, and in the presence of eight upper labials, fourth or third and fourth entering the eye; however, the frequent presence of ocellar spots on the sides, and the low number of ventral shields (147 to 151), show that it should be referred to _T. viperinus_.

_Size._--Rarely reaches a length of 3 feet in Europe, the largest specimens being from Sardinia. An Algerian specimen 3 feet 3 inches long is on record.

_Distribution._--France as far north as Southern Brittany, the Forest of Fontainebleau, and the Department Aube, the whole of the Spanish Peninsula and the Balearic Islands, Southern Switzerland, north and south of the Alps, Liguria, Piedmont, Corsica, Sardinia, and Sicily. In Africa in Morocco, Algeria, and Tunisia, penetrating into the northern parts of the Sahara.

In Liguria, Piedmont, and Ticino, _T. viperinus_ occurs alongside with _T. tessellatus_. It reaches an altitude of nearly 4,000 feet in the Alps.

_Habits._--Very much the same as in the preceding species, although slightly less thoroughly aquatic, large individuals being sometimes met with at some distance from water. Ponds and marshes are the favourite abode of the Viperine Snake, huge numbers being often found on the borders, diving into the water when disturbed. Frogs and toads, tadpoles, newts, fishes, and large earthworms, are its principal food when adult, the young feeding chiefly on batrachian larvæ, young fishes, and earthworms. A case is known of this snake having eaten a water-shrew (_Crossopus fodiens_). When a fish has been caught, it is usually eaten on land; in captivity dead fish are rather readily accepted, provided they be quite fresh. Some specimens bite when handled; others are as gentle as the Grass-snake.

For hibernation, hollow trees, fissures in rocks, holes in the ground or in railway embankments, are selected, and numerous individuals sometimes congregate in the same retreat. In the mild winters of the South of Europe they remain quiet, without being torpid, and resume activity very early in the spring.

In the Alemtejo, according to Gadow, when during the rainless and hot summer the small rivers have nearly dried up, these snakes collect in great quantities in the remaining stagnant and muddy pools, and, as the stock of suitable fish gets exhausted, are often reduced to a deplorably emaciated condition. By the month of August they have become so thoroughly aquatic that they cannot be kept alive in dry surroundings for twenty-four hours, apparently dying from some kind of cutaneous suffocation. The same observer once caught a Viperine Snake in a ditch whilst it was swallowing an eel of nearly its own length.

Some specimens show so great a superficial resemblance to the Common Adder, _Vipera berus_, which, however, being a more northern reptile, very seldom occurs in the same localities--that this snake well deserves its name _Viperinus_. A celebrated herpetologist, Constant Duméril, was once himself deceived by this resemblance and bitten by a _Vipera berus_ which he had picked up in the Forest of Senart, near Paris, believing it to be a _Tropidonotus viperinus_; whilst, conversely, a specimen of the harmless snake was killed in mistake for a Viper by no less an expert than Dr. Viaud-Grandmarais.

_Breeding._--This snake pairs in March and April, and sometimes again in the autumn; but the eggs are only laid at one season, in June or July, and hatch in August, September, or October. The eggs, numbering four to twenty, are deposited in holes not far from water, often in abandoned galleries of voles or moles. The young at birth measure 4 to 6-1/2 inches, and soon resort to the water, where, unlike those of the Grass-snake, they are frequently met with.

GENUS ZAMENIS, WAGLER

Maxillary teeth increasing in size posteriorly, the two last often separated from the others by a narrow interspace. Head elongate, distinct from neck; eye rather large, with round pupil. One or more subocular shields. Body much elongate; scales smooth, with apical pits. Tail long.

The species of this genus, about thirty in number, are distributed over Europe, North Africa, Asia, and North and Central America. Three inhabit Europe.

6. ZAMENIS GEMONENSIS, Laurenti
(_Coluber viridiflavus_, Lacepède; _C. atrovirens_, Shaw)
The European Whip-Snake

_Form._--Slender; snout rounded, with distinct canthus, moderately prominent, concave on each side in front of the eye. Tail three and one-third to four and one-third times in the total length.

_PLATE IV_

_Young, after Sordelli_]

_After Sordelli_]

_Head-Shields._--Rostral a little broader than deep, the portion visible from above measuring one-fourth to two-fifths its distance from the frontal. Frontal more or less bell-shaped, not or but little broader than the supraocular, once and two-thirds to twice as long as broad, as long as or a little longer than its distance from the end of the snout, a little shorter than the parietals. Loreal as long as deep or longer. One preocular (rarely two), extending to the upper surface of the head, but never in contact with the frontal; a small subocular below the preocular; two postoculars (rarely three). Temporals 2 + 2 or 2 + 3 (rarely 1 + 2). Upper labials eight, fourth and fifth entering the eye, fifth and seventh deepest. Five lower labials (rarely four) in contact with the anterior chin-shields, which are usually shorter than the posterior.

_Scales_ with two apical pits, in nineteen (rarely seventeen or twenty-one) rows. Ventral shields more or less distinctly angulate laterally, 160 to 230 (usually under 200 in the typical form and the var. _caspius_, 190 or more in the vars. _viridiflavus_ and _asianus_); anal divided; subcaudals 87 to 131.

_Coloration._--In the typical _Z. gemonensis_ the upper parts are yellowish-brown or pale olive, anteriorly with blackish cross-bars or numerous small black spots, the black scales with a yellowish shaft, the lower parts yellowish-white or pale yellow, rarely more orange; the sides of the head are yellow, the shields edged with blackish. A female, 3-1/4 feet long, from Levico, Trentino, preserved in the Genoa Museum, is uniform reddish-brown above, with mere traces of darker markings on the head and nape. There is every gradation between this form and the var. _viridiflavus_ or _atrovirens_ (Plate IV., third figure), which is dark green or black above, with yellow spots forming transverse series or bars on the anterior part of the body, and longitudinal streaks, following the series of scales, on the posterior part and on the tail; the yellow sometimes predominates over the black, or may appear as a shaft along each dark scale; the preocular and postocular shields are yellow, the labials likewise yellow, with black spots or bars. The lower parts are yellow or greenish-white, with or without black dots, and usually with a series of large black spots on each side.

Some specimens of both the typical form and the var. _viridiflavus_ are entirely black or nearly black. (_Z. carbonarius_, Bonaparte; _Z. sardus_, Suckow). In some localities and islands only black specimens occur.

In the var. _caspius_, Iwan (_trabalis_, Pallas, Plate V., first figure; _persicus_, Jan, Plate IV., second figure), from Hungary, Bosnia, Herzegovina, Corfu, Bulgaria, Roumania, Greece, Turkey, Southern Russia, Northern Asia Minor, and North-West Persia, the upper parts are pale olive or reddish-brown, with or without brown or black spots, and each scale bears a yellowish or pale brown longitudinal streak; there is often a dark longitudinal streak on the nape; the belly is uniform orange or red.

Another variety, var. _asianus_, Boettger, from Asia Minor, Rhodes, Cyprus, and Syria, has the upper parts brown or olive, each scale with a longitudinal light streak, and there are usually large black spots relieved by yellowish shafts; the belly is red, spotted or dotted with black. Melanism is frequent in this form, such specimens being entirely black except on the chin and throat, which are yellow variegated with red.

The very young of the typical form, as well as that of the var. _viridiflavus_, has a striking livery (Plate IV., first figure), the head and nape black with yellow markings, or olive with black-edged yellow markings, contrasting sharply with the pale olive-grey of the body; the most conspicuous and constant of the yellow markings consist of a bar between the eyes, interrupted on the frontal shield, but sometimes continuous with the yellow of the postoculars, five or six small round spots on the parietal shields, and a V- or W-shaped line just behind the parietals, followed by one or two others separating the dark cross-bars which may be present on the nape, and occasionally even continue some way down the anterior part of the body. This livery persists in some half-grown specimens.

In young individuals from Syria (var. _asianus_) the head is not differently coloured from the olive-brown body, and the markings described above appear as mere traces; on the other hand, the whole body has black and yellow spots or cross-bars above, and the belly is profusely marked with round black spots.

In the new-born of the var. _caspius_, of which I have examined only one specimen, 11 inches long, from the Crimea, the head is olive-brown like the body, which bears dark brown spots and narrow cross-bars; and there is a dark brown streak along the middle of the nape, as is sometimes the case in the typical form. The belly is unspotted. A young from Malta is intermediate in its markings between the typical form and this variety.

The young of the so-called black variety are not black at birth, but similar to the normal young of the races to which they belong.

The four principal forms--_viridiflavus_, _gemonensis_, _caspius_, and _asianus_--are so completely connected that I cannot regard them as more than geographical races or varieties.

_Size._--This handsome snake grows to a length of 6 feet, the var. _caspius_ even to 8 feet. I have seen a specimen of this variety, from Salonica, which measures 7-2/3 feet.