SNAKE CHARACTERS. 301 



innocuous Snakes. Moreover, there are some peculiar anatomical arrangements in them not noticed 

 in the Vipers. Hence, the poisonous Snakes are divided into two groups the Viperifomi Snakes 

 and the Venomous Colubrines and the innocuous Snakes are the True Colubrines. 



A great number of Snakes live on the ground, rarely, if ever, taking to trees. They have a 

 very flexible body, which is more or less cylindrical in shape, and amongst them are Vipers 

 (Viperiform Snakes), venomous Colubrine Snakes, and innocuous Snakes (Colubrine Snakes) 

 in fact, all the divisions. A few harmless Snakes (Colubrines) live a bui-rowing life under ground, 

 and have rather a rigid, round body and a small mouth. Finally, there are several kinds of 

 Water Snakes. Those which frequent fresh water are harmless Colubrines, bvit those which live in 

 the sea are all poisonous, and belong to the venomous Colubrines, and not to the Viperiform division. 

 All have a long, forked, proti'actile tongue. 



On looking at a Snake carefully, taking the Common English Spotted Snake as an example, no 

 difficulty is found in distinguishing the head from the rest, and it is evident that there are no limbs, 

 but what is neck, body, and tail is not at first so readily determined. The neck is, of course, the part 

 behind the head, and it merges gradually into the body, there being no place of division ; but the tail, 

 although not very distinguishable on the top of the Snake, is so beneath, for it is placed behind the 

 part from which the evacuations come, and its scales are arranged differently to those in front, they 

 being in double rows, whilst all those of the underneath part of the body are in a single row. 



With very few exceptions, the Snakes of all the divisions are covered with scales, and there may 

 be plates on the head. The scales are not bony, but are true skin structures, and they are occasionally 

 shed, new ones appearing. The presence of plates on the head, the arrangement and character of the 

 scales on and under the body and tail, their colour and ornamentation, are all useful in the classifica- 

 tion of these reptiles, for they are very persistent characters, if the coloration is excepted, for this is 

 often very vaiiable in the same species in the same country. The shape of the head, and the relation 

 of the size of the body and tail, are also important distinctive characters, and the anatomy of the 

 skull, jaws, and teeth is of the greatest value in the primaiy separation into great groups. 



But although there is no difficulty in distinguishing a Viper, a Boa Constrictor, or a Common 

 Snake from any other animal, it must be remembered that there are some Saurians which closely 

 resemble some of the Snakes. Amphisbsena (p. 294), and Anguis (the Blind-worm), and Acontias and 

 Pseudopus (pp. 298, 299) are Snake-like and have no limbs. On the other hand, it has been found that 

 such great Snakes as the Boas, for instance, and, indeed, all the species of a Snake family (the 

 Pythonides), have minute vestiges of hind limbs, scale-like or spine-like, close to the vent ; and this 

 peculiarity recalls to the student the Lizards of the peculiar Australian kind (Pygopus), and the 

 Brazilian Ophiodes. Moreover, amongst the Amphibia, which have not as yet been considered in this 

 work, there is a Snake-like form called Csecilia. These resemblances are not entirely confined to the 

 outside, for some of the Sauria have one of the lungs ill-developed, the other preponderating, and 

 this is found in all the Snakes. Moreover, although the great majority of the Serpents swallow their 

 food whole, by means of a special mechanism which permits distention of the jaws and throat, some 

 consume such small prey that there is not this gift. And in the absence of this very common charac- 

 teristic, many of the smaller Colubrine Snakes resemble some of the Snake-like Lizards. But on 

 examining the internal organs, and especially the bony framework of the Snake's body, the distinctness 

 of the order Ophidia from that of the Saurians becomes more and more evident. No Snake has 

 a shoulder girdle, and the eyelids, the covering of the tympanum, and the bladder are wanting. 



In considering this inability to separate the great groups of Snakes and Lizards by outside 

 characters in some instances, and by some internal ones also, it becomes evident that there 

 is no hard and fast line to be drawn between them. Moreover, study gradually develops the 

 thought that the Snakes, coming late into being in the world's history are, like the limb- 

 less Lizards, modifications, by a degenerative process, of reptiles which did not crawl on their 

 belly, but which had those organs in peiiection which are rudimentary or absent in the Serpent. 

 Beautiful to look at, glistening often with an iridescence which adds to their mosaic of lovely colours, 

 moving with great grace, apparently with an incomprehensible and determinate will, seizing their 

 prey to crush it and swallow it, or to destroy it by poison in a few minutes, no wonder that early man 

 worshipped these emblems of destruction and death, and gave them credit for wisdom and power. 

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