BOAS.- 



-EEPTILES. Boas. 



53 



in his "Description of Guinea and the Gold Coast," 

 informs us that though the largest he saw himself was 

 twenty feet, that there existed many much larger in 

 the interior, where his countrymen often found in their 

 stomachs not only whole animals, but men entire. 

 Labat tells us that on the river Kurbali, on the west 

 coast of Africa, serpents are to be seen thirty feet long, 

 and capable of swallowing an ox ; and in the Moluccas 

 we are told of serpents upwards of thirty feet in length 

 and one foot in circumfereuoe. Schlegel, however, a 

 cautious and conscientious author, remarks upon this 

 subject, that though the Boa constrictor is generally 

 held up as of an enormous size, he is perfectly satisfied 

 that it rarely attains a length of nine or ten feet ; that 

 the largest Pythons seldom exceed eighteen or twenty; 

 and that the Anaconda itself (the largest species of tlie 

 family) is now-a-days never met with exceeding twenty 

 or twenty-five feet, and of the circumference of a man's 

 thigh. M. Boie, who in his travels in India had many 

 opportunities of observing these animals, tells us that in 

 spite of his assiduous researches he was never able to 

 procure Pythons even of the size we have mentioned.* 

 It is said that after having killed their prey, they 

 lubricate the body all over with a thick layer of saliva, 

 in order to accelerate its putrefaction and facilitate its 

 deglutition. Now, says Schlegel, the mouth of the 

 Boas is really not wider than in many other serpents, 

 the jaws are not more dilatable, and the salivary glands, 

 which ought to be able to secrete such a prodigious 

 quantity of saliva, and therefore ought to be very large, 

 are on the contrary much less developed than in a 

 great number of other serpents. Mr. Broderip, in tlie 

 article Boidm in the English Cyclopedia says, " There 

 is generally in these descriptions an account of the fleshy 

 tongue of the reptile, and of its application to the dead 

 animal for the purpose of covering it with saliva previous 

 to the operation of swallowing it. We have fre- 

 quentl}' watched constricting serpents while taking their 

 prey,and it is almost superfluous to add that they never 

 covered their victim with saliva from their tongue before 

 deglutition. The mucus is not poured out till it is 

 required to lubricate the dilated jaws and throat for the 

 disproportioned feast." M. Boie, quoted above, in 

 India, and the Prince of Neuwied, in America, agree in 

 stating that these large reptiles only prey in general upon 

 mammalia of a small size, adult individuals alone being 

 able to master young pigs and those small deer known 

 by the name of Muntjac. Large mammalia and man, 

 they aflirm, are never in danger of being attacked by 

 these creatures, and the natives could not infonn them 

 of even a child having ever run any risk. Enough of 

 sober truth, however, remains to make the study of 

 these large serpents exceedingly interesting. The body 

 diminishes in size gradually towards the two extremities, 

 being much thicker in the middle. It is always con- 

 siderably compressed. The tail is short, somewhat 

 conical, and most frequently terminated in a short, blunt 

 point. It is always prehensile — that is, owing to the 

 direction of the articular surfaces of the vertebraj it can 



• The largest specimens of stuffed snakes in the coUectidn 

 of the British Museum are as follows : — Python tSchiv, fifteen 

 feet ; Boa constrictor^ thirteen feet ; and Anaconda^ twelve 

 feet. 



easily roll itself inwardly, fasten itself to objects which 

 permit themselves to be laid hold of, and is thus able 

 to sustain the weight of the whole body without the 

 serpent being obliged to employ much force for that 

 purpose. The head is always distinct from the trunk, 

 broad, rather long, conical, depressed, and terminated 

 by a muzzle, which is most frequently elongated and 

 blunt at the tip. The plates or scales which cover 

 the edges of the lips (the lahial j'lates) are in a number 

 of species (more particularly the Pythons) hollowed 

 out in the form of more or less deep pits, an organiza- 

 tion peculiar to these animals, and of which we do not 

 know the use. The bones of the head are exceedingly 

 strong. Tlie teeth are pretty large, all solid, close set, 

 aud pointing backwards, and increase in size as tliey 

 approach the tip of the muzzle. The palate is in 

 general provided with teeth also, nearly as well 

 developed as those of the jaws. The ribs are robust, 

 long, and curved; and the articulating surfaces of the 

 vertebri-e are directed in such a way that tlie body 

 of the serpent can easily be rolled spirally inwards. 

 We have already alluded to the existence of rudi- 

 mentary hinder extremities in this family. These 

 consist of a legbone, or tibia, two tarsal bones, and 

 a metatarsal bone, all developed imder the skin, and 

 to the last of which is attached a homy spur, or nail, 

 which penetrates the skin and projects externally. — See 

 Plate 8, fig. 18. Tliese spurs are moved by small 

 muscles attached to the bones, and are useful to tlie 

 animal in chmbing trees and perhaps in holding fast its 

 prey. Boas are endowed with prodigious muscular 

 force, and though this may be also exaggerated, we 

 may yet conceive, from an inspection of the muscles 

 attached to the ribs, of what amazing power a serpent 

 twenty feet long, and as thick as a man's thigh, may 

 really possess. 



They are very rarely seen, however, to use this 

 power in captivity. Such as have been seen in Europe 

 are generally very gentle, no provocation bemg able to 

 incite them to put forth their strength, and their move- 

 ments are very slow. They are, many of them, of 

 brilliant colours, though tliese disappear after death. 

 Unlike the generality of serpents, their colours do not 

 become pale with age, but, on the contrary, become 

 more vivid, the design remaining very distinct at all 

 periods of tlieir life. "As far as our experience goes," 

 says Schlegel, " the females appear to be thicker in the 

 body than the males, while the rudimentary legs, on the 

 other hand, appear to be more strongly developed in 

 the male than in the female." The Boas are well known 

 to take their prey by stratagem. "Hot steaming 

 morasses, the swampy margin of rivers, the borders of 

 lakes, the tangled underwood that skirts the dark and 

 marshy forest — these are their favourite abodes ;" and 

 there, with its prehensile tail twisted round some 

 aquatic shrub or tree, the huge reptile lies m wait 

 silently and patiently, stretched on the bank, or half 

 floating ui the water, till some unfortunate animal 

 chance to pass that way, or ventures to the water to 

 quench its thirst, when, with amazing velocity, it darts 

 upon its victim, seizes it witli its sharp strong teeth, 

 and, with the quickness of thought, twists its huge bulk 

 in many folds round the body of its prey, and crushes 



