1C6 



MUSEUM OF ANIMATED NATURE. 



[Sehpents. 



three miles digtant, about a week aner its liberation, \ 

 and three others were shortly afterwards killed i 

 within that distance of the place where they were 

 turned out, and it is highly probable that the 

 remaining two met with a similar fate, falling 

 victims to a reward which was offered for their 

 desti-uction.'" It would appear then, that though 

 the snake is not indigenous in Ireland, there is 

 nothing in the climate to prevent its naturalization. 



There are no snakes in New Zealand, but on one 

 occasion several dead sea-snakes were driven on 

 the coast, to the consternation of the natives : one of 

 these was presented to the Zool. Soc. (See ' Pro- 

 ceeds.' 1838, p. 4.) ,.,,.. 



In the great Polynesian groups of islands these 

 reptiles are not found, with a remarkable excep- 

 tion, recorded by the late Mr. Williams, of the 

 London Missionary Society, whose tragical fate is 

 so well known. In his narrative he thus writes 

 respecting the Samoa Islands, oflen termed the 

 Navieators' : — Snakes also, wliich are unknown at 

 the Tahitian and Hervey groups, abound here; I 

 was informed that there were several species of 

 them, some of which are beautifully variegated. 

 Those procured for me were of a dark olive colour, 

 about three feet long. There are also water-snakes, 

 some of them beautifully marked with longitudinal 

 stripes of yellow and black, and others with rings 

 alternately white and black. The natives esteem 

 both the land and sea snakes good food. In the 

 disorder occasioned by the leak in our ship, and her 

 subsequent sinking at Tongatabu, I lost my snakes 

 and manv other curiosities which I was conveying 

 home." 'To this he adds the following information : 

 " Very large lizards are found on the mountains of 

 Savaii and Upolo; and from the description I 

 received I should conclude they were guanas. 

 None, however, of these reptiles are venomous.* 

 Another peculiarity in the natural history of the 

 group is that a wild dog is found in the mountains ; 

 I regretted exceedingly that I could not obtain one. 

 From the description I received it appears to be a 

 small animal of a dark dirty grey or lead colour, 

 with little or no hair, and large erect eare." 



Somewhat unsatisfactory and unsettled are the 

 genera into which the order Ophidia is divided ; it 

 may be observed, however, that these reptiles pri- 

 marily resolve themselves into three distinct sec- 

 tions, viz., innoxious, poisonous, and aquatic, each 

 section having its own characteristics. 



Looking at the ophidian reptiles generally, we 

 may describe them as of elongated form, with the 

 head distinct, possessing great flexibility and 

 strength. The mouth is wide and dilatable, the 

 eyes are bright, there are no external auditoiy 

 orifices, nor are there any limbs, but in some, as the 

 Boas, the posterior pair, as we shall hereafter more 

 fully explain, exist in the form of stylets, and assist 

 the tail in grasping. 



The top of the head is covered with plates, some- 

 times with scales, resembling those of the upper 

 surface, which are small or moderate, more or less 

 acutely pointed, and imbricated ; these are termed 

 squamcB. The scales of the under surface are broad 

 and transverse, and the posterior edge of each over- 

 lays the anterior margin of the one succeeding. 

 These transverse under-plates are termed scuta. 



The eyes are exposed, being undefended by eye- 

 lids, but the surface of the cornea is covered by a 

 transparent continuation of a delicate epidermic 

 membrane which invests the scales, and which is 

 frequently cast off, the animal emerging in brighter 

 colours and with renewed strength and activity. 

 This epidermic investment is known as the slough 

 of the snake. If we look at the skeleton of the 

 snake, and we take for our example that of dne of 

 the non-venomous snakes called pythons (see Fig. 

 2239), we shall be surprised at the beautiful arrange- 

 ment of its component parts, at the number of the 

 vertebra and the ribs, and a little investigation will 

 serve to show how admirably it is adapted for flexi- 

 bility and strength. 



If we attend first to the spinal column, of which 

 two vertebrse are represented at Fig. 2240, we shall 

 find that the bones are united together by ball and 

 socket articulations, or in other words, that the 

 rounded head of each is fitted into a cup-like cayily 

 of its predecessor, so that the whole column is a 

 chain of these joints, by which the vertebrse are 

 firmly locked together, but which at the same time 

 permit the utmost degree of mobility compatible 

 with the safetv of the spinal cord. The various 

 processes for the attachment of muscles are very 

 prominent, and on the under surface, as seen at Fig. 

 2240, a a, are protuberances for the attachment of 

 constricting muscles, by the action of which the 

 python or boa crushes his victim. 



To the vertebrae thus united are attached the ribs, 

 and these are so ordered as to become efficient or- 

 gans of locomotion ; a circumstance first discovered 

 by Tyson, and recorded in his observations on the 



Thla it not q<iii« coirect ; the lea-makes ue exceedingly venomoiu. 



anatomy of the rattlesnake (' Phil. Trans.*). Sir 

 Joseph lianks subsequenily noticed it in the com- 

 mon snake. 



From every vertebral bone, those of the tail ex- 

 cepted, arises on each side an arched rib, capable 

 of a certain degree of motion, being articulated upon 

 a convex protuberance, and acted upon by powerful 

 muscles, which advance or retract it. Instead of 

 being attached by their extremity to a sternum or 

 breast-bone, each pair of ribs is connected to one 

 of the abdominal scuta, by means of a slender car- 

 tilage and a set of short muscles. It is on the 

 points of these ribs, which may be compared to the 

 legs of a millipede, that the snake rests, and they 

 act in progressive order, as we see the legs of that 

 creature, each pair bringing forward the plate or 

 scutum to which it is attached, and which may be 

 regarded as their common foot. If a snake be al- 

 lowed quietly to crawl over the hand, the progres- 

 sive movements of the ribs may be easily distin- 

 guished, and also, if it be watched while crawling 

 over any raised edge, as the back of a book, re- 

 quiring the firm application of two or three scuta 

 in succession as the body glides over it. According 

 to Sir E. Home, the muscles which bring forward 

 the ribs consist of five sets, besides other internal 

 muscles. 



The ordinary movement of a serpent is sinuous, 

 its body assuming a series of gentle flexures, while 

 the ribs, which are expanded, bring forward the 

 abdominal scuta in succession ; the posterior edge 

 of each laying hold as it were of the ground, and 

 becoming a fixed point from which to set out anew. 

 When the snake proceeds rapidly, the flexures of 

 its body are more ample and acute, and in this 

 manner, making a series of undulations from side to 

 side, it glides along with great velocity. These 

 animals can also proceed by a series of bounds, 

 by springing either from the tail or hinder half of 

 the body, but their structure forbids their progress 

 by vertical undulations, as they are often represented 

 in the older, works. Most can climb trees, some, in- 

 deed, are arboreal, and they swim and dive with 

 facility and grace. Many serpents can leap or throw 

 themselves to a great distance ; in some instances 

 they coil themselves up spirally, then instantaneously 

 relaxing the muscles of one side, and at the same 

 instant calling into action those of the outer side, 

 they propel themselves with great quickness on 

 their prey; the projectile impulse resembling that 

 of a slender spring coiled up spirally, pressed on 

 the table, and suddenly released. 



The .skull of the serpent presents us with a very 

 curious structure. It is well known that these ani- 

 mals swallow prey far exceeding their own body in 

 bulk, and that the jaws adapt themselves to the 

 mass, which is gradually gorged • they are, in fact, 

 dislocated altogether during the act, and subse- 

 quently recover themselves. Let us look at the 

 skull of a large python, represented at Figs. 2241, 

 2242, and 2243 (as seen from above, a palatal view, 

 and in profile), we shall find that most of the bones 

 composing it, instead of being locked together as 

 in mammalia, are separate, and only retained in 

 their places by skin ligaments and muscles. The 

 upper jaw, see Fig. 2241, is composed of two dis- 

 tinct branches, separate from the bones of the skull, 

 with a distinct intermaxillary bone between the 

 points of each ; and it will be found, moreover, that 

 the bones of the face continue in their elemental 

 state of subdivision, and are all disunited ex- 

 cepting by means of a fibrous elastic tissue. The 

 lower jaw (Fig. 2243) consists also of two distinct 

 lateral branches, disunited at the symphysis ; each 

 branch, which consists of two portions united by a 

 lax kind of suture, is connected to the skull by two 

 moveable bones, namely, an elongated tympanic 

 bone, and a mastoidean bone ; the attachment of 

 these bones together, and to the skull, is merely by 

 ligaments and muscles, so that when the jaws are 

 straining in the act of ingulfing pity, the articu- 

 lations admit of a natural dislocation ; at the same 

 time the skin, muscles of the neck and throat, and 

 the gullet, are capable of enormous extension, the 

 animal appearing as if ready to burst, while the 

 working of the muscles, stretched as they are, is 

 very palpable. During this operation it might be 

 supposed that the snake would be suffocated, but it 

 is found that the larynx is protruded beyond the 

 edge of the dilated lower jaw, as was first noticed 

 by Mr. Broderip ; and Mr. Green has detected two 

 muscles specially adapted to draw the larynx for- 

 wards during the act of deglutition. 



From what we have said it will be perceived that 

 serpents do not masticate their food ; hence are their 

 teeth adapted for seizing and retaining living prey. 

 We pass for the present a consideration of the 

 poison fangs of venomous serpents, confining our 

 observations to the teeth of the non-venomous. 

 They are simple, conical, sharp, and directed back- 

 wards ; above there are four rows, viz., a row in 

 each branch of the upper jaw, including the inter- 

 maxillary bone, and a row on each side of the palate. 



roofed in the palatine and pterygoid bones : a row 

 of teeth crowns the ridge of the anterior portion of 

 each ramus of the lower jaw. The number of teeth 

 vary in different species ; sometimes they are nearly 

 all equal in length, or, as in the Boas and Pythons, 

 the anterior teeth are the largest, the decrease 

 being gradual as they recede backwards ; in some, 

 however, the back teeth are the largest, and in 

 others a few teeth exceeding the rest are in the 

 centre of each row. In the genus Deirodon (Anodon, 

 Smith) the teeth are so small as to be scarcely per- 

 ceptible, and besides so soon lost that the snakes 

 of this genus have been regarded as toothless. These 

 reptiles feed almost exclusively, if not entirely so, 

 on the eggs of birds ; and, as Professor Owen ob- 

 serves, "If the teeth had existed of the ordinary 

 form and proportion, in the maxillary and palatal 

 regions, the egg would have been broken as soon as 

 it was seized, and much of its nutritious contents 

 would have escaped from the lipless mouth of the 

 snake in the act of deglutition ; but, owing to the 

 almost edentulous state of the jaws, the egg glides 

 along the expanded opening unbroken, and it is 

 not until it has reached the gullet, and the closed 

 mouth prevents any escape of the nutritious matter, 

 that the shell is exposed'to instruments adapted for 

 its perforation. These instruments consist of the 

 inferior spinous processes of the seven or eight pos- 

 terior cervical vertebrse, the extremities of which 

 are capped by a layer of hard cement, and penetrate 

 the dorsal (upper) parietes of the oesophagus; they 

 may be readily seen even in very young subjects, 

 in the interior of that tube, in which their points 

 are directed backwards. The shell being sawed 

 open longitudinally by these vertdrral teeth, the 

 egg is crushed by the contractions of the gullet, and 

 is carried to the stomach, where the shell is no 

 doubt soon dissolved by the gastric juice " (' Odon- 

 tography '). 



To the skull and teeth of the venomous serpents 

 we shall invite attention when we come to our pic- 

 torial specimens of that dreaded group. 



The lungs in snakes are either single, as in the 

 common snake, or double, as in the python ; the 

 right lung, however, being the most extensively de- 

 veloped as a reservoir for air. The upper portion 

 of the lung or lungs is spongy or cellular, and highly 

 vascular, and it is in this portion that the change in 

 the blood is effected ; gradually the spongy struc- 

 ture, through the centre of which a free passage is 

 left, merges into a thin membranous and but 

 slightly vascular sac, serving as a reservoir for air. 



The voice of serpents when excited is a hissing 

 noise more or less loud ; the tongue is long, moist, 

 deeply forked, vibratory, and capable of being 

 moved in all directions ; when withdrawn it is re- 

 ceived into a sheath, which can be either elongated 

 or contracted. The sense of taste is evidently little 

 developed, nor is that of smell very acute. 



Serpents, like the reptile tribes in general, hy- 

 bemate in temperate regions, but within the tropics 

 their torpor depends on the continuance of drought; 

 in this case, as Mr. Darwin well observes, the terra 

 hybernation ought to be exchanged for aestivation. 

 " Near Rio de Janeiro," he says, " I was at first sur- 

 prised to observe that a few days after some little 

 depressions had been changed into pools of water 

 by the rain, they were peopled by numerous full- 

 grown shells and beetles. Humboldt has related a 

 strange accident of a hovel having been erected 

 over a spot where a young crocodile lay buried in 

 the hardened mud ; he adds, the Indians often find 

 enormous boas, which they call Uji, or water-ser- 

 pents, in the same lethargic state ; to reanimate 

 them they must be irritated or wetted with water." 



Serpents are extremely tenacious of life, and in- 

 stances have been known in which the head severed 

 from the body has not only long retained vitality, but 

 bitten with fury : we had once a viper which, although 

 deprived of the posterior portion of the body by the 

 blow of a stick, lived for several days. With respect 

 to the natural duration of life in these animals little 

 is positively known, but doubtless it is very pro- 

 tracted, and years must elapse before a boa, which 

 when first excluded from the egg does not exceed 

 two feet in length, acquires that of thirty. The 

 ancients believed that when they threw off their 

 slough they renewed their youth, with a brighter 

 robe, the index of fresh vigour. 



It has been a belief of long standing that snakes 

 possess the power of fascinating their victims: of 

 paralyzing the bird or squirrel, or even of attracting 

 it till it advances to the very jaws of the ferocious 

 reptile. Dr. Smith, in his ' Zoology of South 

 Africa,' speaking of the Boomslange (Bucephalus 

 Capensis), which is generally found on trees, to 

 which it resorts for the purpose of catching birds, 

 adds, "The presence of a specimen in a tree is ge- 

 nerally soon discovered by the birds in the neigh- 

 bourhood, which collect round it and fly to and fro, 

 uttering the most piercing cries, till one more terror- 

 struck than the rest actually scans its lips, end 

 almost without resistance becomes a meal for its 



