SERPENTIA. 183 



BOA, Linntsus*, 



Formerly comprised all those serpents, venomous or not, the under part of 

 whose body and tail is furnished with uninterrupted transverse scaly bands, 

 and which have neither spur nor rattle at the end of the tail. As they are 

 rather numerous, even after deducting the venomous species, the others have 

 been again subdivided. 



The BOA, properly so called, has a compressed body, thickest in the middle, 

 a prehensile tail, and small scales on the head, at least on its posterior portion. 

 It is in this genus that are found the largest serpents on the globe; certain 

 species attain a length of thirty or forty feet, preying on dogs, deer, and even 

 oxen, which they manage to swallow entire, after having crushed them in their 

 folds, and covered them with saliva. This operation requires much time, and 

 an enormous dilatation of their jaws and throat. Their small lung is but half 

 the length of the other. 



Boa constrictor, Lin. Known by a broad chain, which extends along the 

 back, formed alternately by large, blackish, irregular hexagonal spots, and by 

 pale oval ones, the two ends of which are emarginate. 



The celebrated Anaconda is a true Boa. 



COLUBER, Linticeus. 



This genus comprises all those serpents, venomous or not, whose sub-caudal 

 plates are divided in two, that is, which are arranged by pairs. Independently 

 of the subtraction of the venomous species, their number is so enormously 

 great, that naturalists have had recourse to all sorts of characters to subdivide 

 them. In the subgenus Python we find the CoLjavaniacus, Sh., which has 

 been found thirty feet in length. Found in the Sunda Islands. 



Serpents which are venomous par excellence, or those with isolated fangs, 

 have their organs of manducation constructed on a very peculiar plan. 



Their superior maxillary bones are very small, attached to a long pedicle, 

 analogous to the external pterygoid apophysis of the sphenoid bone, and are 

 very moveable; in them is fixed a sharp-pointed pervious tooth, through which 

 flows a liquor secreted by a large gland, situated under the eye. It is this 

 liquor which, poured into the wound made by the tooth, produces effects, more 

 or less violent, according to the species of the reptile in which it is secreted. 

 This tooth, when the animal does not wish to use it, is concealed in a fold of 

 the gum, and behind it are several germs destined to replace it, in the event of 

 its being broken in a wound. These venomous teeth have been termed by 



* Boa, the name of certain Italian Serpents of great size, most probably the four striped 

 Coluber, or " Serpent of Epidauras " of the Latins. Pliny says they were thus named, 

 because they sucked the teats of cows. The Boa, ] 20 feet long, which it is pretended was 

 killed in Africa by the army of Regulus, was probably a Python. See Pliny, lib. viii. 

 cap. xiv 



