510 OPHIDIANS. 



beautiful and striking instances of marked adaptation and har 

 mony, so extensively apparent in the works of God. 



Serpents can hardly be said to have two lungs, one of the two 

 being generally abortive, or merely rudimentary. 



All of them have teeth, but these serve only to retain their 

 food, and are not adapted to mastication. In the harmless snakes, 

 (or rather those which are not poisonous,) the upper and under 

 jaws are furnished with a number of small, but very sharp teeth, 

 pointing backwards, (Plate XII. fig. 5 ;) the palate is also armed 

 with two similar rows, so that there are six lines of teeth in the 

 mouth. The venomous species not only have the jaws very 

 small and freely movable upon a bony peduncle or footstalk ; 

 but each branch of the upper jaw has a long, recurved, pointed 

 tooth, traversed by a canal or tube, leading from a large gland 

 situated beneath the eye. The fluid secreted by the gland passes 

 through this tube into the bottom of the wound which the poison- 

 fang inflicts. When not call-ed into use, the poison-fangs lie 

 concealed along the roof of the mouth ; but when about to bite, 

 the snake raises them up, and in the act of biting, compresses 

 the poison-glands, by means of a peculiar muscle for that pur 

 pose, and thus instils a few drops of the deadly fluid into the 

 puncture. These large fangs are, in truth, the only teeth in the 

 upper jaw, the others above are arranged in two rows on each 

 side, along the bones of the palate. The branches forming the 

 lower jaw are slender, and but partially furnished with teeth. 



It is common to hear persons speak of the sting of the serpent ; 

 but from the explanation here given, it will be noticed that prop 

 erly speaking, the serpent has no sting; the fatal wound is pro 

 duced by a bite. 



Most species of venomous serpents are ovo-viviparous, i. e., 

 the young are hatched before exclusion and born alive, whence 

 the general name of Vipers a contraction of Vivipares, (born 

 alive) though with a few of this division, whether they be so 

 born or not, seems a matter dependent on the latitude and the 

 mean temperature of the region in which they dwell. Some of 

 the non-venomous or harmless snakes are also ovo-viviparous; 

 the others are oviparous. The eggs are often more than thirty 

 in number, rounded and agglutinated in bead-like rows, by a 

 sort of mucous substance. The shells of the egg in oviparous 

 serpents, although cretaceous, are soft like the eggs of the com 

 mon hen when she has not enough calcareous matter in her food, 

 called soft eggs. Their color is ordinarily yellowish or grayish 

 white. The Creator has in this as in other instances, benefi 

 cently provided against the increase of dangerous animals, by 



