Wood Serpents.- 



-KEPTILES.- 



-Tree Serpents. 



63 



{Ucrpctodryas flagelliformis) is one of the most re- 

 markable species of the family The neck of this 

 serpent is small, and the body very long. The tail is 

 long and slender, one-fourth the length of the body, 

 and attenuated like a piece of whip-cord, which it 

 further resembles in appearance from the peculiar 

 arrangement and form of the scales. It is from this cir- 

 cumstance that it has derived its name. The upper part 

 of the head and neck, and nearly a third of the body, 

 are of a glossy raven-black colour, gradually becoming 

 paler as it approaches the tail, which is of a light 

 brown or tawny colour. The colour, however, varies 

 very much, as they have been seen of a cream colour, 

 a clay colour, and sometimes almost white, but always 

 raven-black near the head. Catesby was the first to 

 describe the Coach-whip Snake. He sa3's : — " This 

 is a very long, slender snake, particularly the hind 

 part ; it diminishes gradually to the tail, and from the 

 resemlilance of a coach-whip has received its name. 

 The colour of it is brown ; it is very active and nimble, 

 running very swiftly. They are inoffensive, yet the 

 Indians report (not without gaining many proselytes 

 to their silly belief) that they will by a jerk of the tail 

 separate a man in two parts." It is inotfensive in its 

 manners, but defends itself with great dexterity when 

 attacked, by twining its long body round the enemy. 

 Bartram witnessed such a scene, and thus describes it. 

 When riding along he observed, he says, " a large 

 hawk on the ground in the middle of the road. When 

 coming up near him I found him bound up by a very 

 long coach-whip snake, that had wreathed itself several 

 times round the hawk's body, who had but one of its 

 wings at liberty. Beholding their struggles a while, I 

 alighted off my horse with the intention of parting 

 them ; when, on coming up, they mutually agreed to 

 separate, each seeking his own safety, probably con- 

 sidering me as their common enemy." According to 

 Mr. Holbrook, though in general this serpent is about 

 five feet long, individuals are said to occur seven feet 

 in length. 



Passing over the next family of Innocuous Serpents, 

 the Psammophklce, which have nothing particularly 

 interesting in them, and which muster only about 

 eight species in all, we come to — 



Family VII.— THE SPINE-TOOTHED 

 SERPENTS {Rachiodontida;). 



This family is small in number, but very interesting 

 from the peculiar method of dentition or contbrmation 

 of their teeth. Only two species are known, and both 

 are natives of Africa. They are almost destitute of 

 maxillary teeth, having only from four to seven in 

 their mouth, and these exceedingly small. Their 

 throat or gullet, however, is furnished with a series of 

 instruments which supply the place of teeth, and are 

 admiral)ly contrived for enabling the reptile to take its 

 natural food. This consists of the eggs of birds ; and 

 the instruments in the throat supplying the place of 

 teeth, consist of the inferior spinous processes of the 

 seven or eight vertebr;u of the neck, the extremities of 

 wdiich are capjied by a layer of hard cement, and 

 penetrate through the upper surface of the gullet. 



Sir Andrew Smith and Professor Owen have both par- 

 ticularly pointed out this curious contrivance, and 

 wonderful adaptation of means to an end. The latter, 

 in his " Odontography," observes—" 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 nutri- 

 tious 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 till it has reached the gullet, and the closed 

 mouth prevents any escajie of the nutritious matter, 

 that the shell is exposed to instruments adapted for its 

 perforation." 



THE ROUGH SPINE-TOOTH (Dasypelti's scahrn)—(\2;. 

 18 — is a native of the Cape of Good Hope, in the south- 

 eastern districts of the colony and in Kaffirland, and 

 is frequently found concealed under the loose bark of 



Fig. 18. 



I — ^y 



The Rough Spine-tooth (Dasypeltis scabra). 



dead trees. Sir Andrew Smith had frequent oppor- 

 tunities of seeing this reptile in a living state, and 

 found that it subsisted entirely on eggs. After describing 

 it at some length, he says : — " The jiaucity and small- 

 ness of the teeth in the mouth are favourable to the 

 passage of the egg, and permit it to progress without 

 injury, whereas, were they otherwise, many eggs 

 which have very thin shells would be broken before 

 they entered the gullet, and the animal in consequence 

 would be deprived of its natural food when within its 

 reach. The instant the egg is broken by the exertions 

 of the animal, the shell is ejected from the mouth, and 

 the tluid contents is conveyed onwards to the stomach." 



Family VIIL— THE TREE SERPENTS 



[Dendroph idee) . 



The Tree Serpents are particularly adapted for 

 inhabiting the vast forests of hot climates, and are 

 more particularly abundant in America and India. 

 They usually have a very elongated form, attaining a 

 length of four or five feet, and only a thickness of the 

 little finger. The tail, being very fine and slender, 

 round or flattened underneatli, is well calculated for 

 assisting these animals to cling to the branches ot 

 trees, to suspend themselves there while they lie in 

 wait for their prey ; while at the same time it seconds 



