It is said that, in the Circassian slave-market, a young woman that blushes fetches a higher price. Some complexions do not show the increased flow of blood in this way, and all persons are not equally sensitive to the cerebral shock that causes it.
BOA, in popular language, the name of all those large serpents which kill their prey by entwining themselves around it, and constricting It in their coils; but by zoologists of the present day, limited as the name of a genus to a very small portion of their num ber, all of which are natives of the warm parts of America—the similar large serpents of Asia and Africa forming the genus python (q.v.). The name B.. however, was cer tainly not originally applied to American serpents, for it is used by Pliny, who accounts for its origin by a fable of serpents sucking the milk of cows, thus referring it, very improbably. to the Latin bos, an ox. The Linntean genus 13. comprehended all serpents having simple subcaudal plates, but without spur or rattle at the end of the tail, and was thus very artificial, as founded chiefly upon a single unimportant char acter, and consisted of a very miscellaneous assemblage of species, venomous and non venomous. The B. family, or boithe, as now constituted (containing the pythons, etc., of the old world, as well as the true boas of the new), is almost exclusively confined to tropical climates, and all the species are of large size and great strength, some of tneut far exceeding in these respects all other serpents. The story related by the ancients of a serpent 110 ft. in length, which devoured several soldiers, and caused alarm to a Boman army in Africa, may perhaps be deemed unworthy of credit, although the skin is said to have been long preserved at Rome; but there is good reason to believe that serpents in more modern times have attained at least half this length, and have made even the larger mammalia, and sometimes man, their prey. The boidce are not venom ous; but their mouth, although destitute of poison-fangs, is so furnished with teeth as to make their bite very severe. Their teeth are numerous, long, and directed backwards, so as the more effectually to prevent the escape of the prey, which is first seized by the mouth, and then the serpent, with a rapidity of motion which the eye of the closest observer fails perfectly to follow, coils itself around it; the powerful muscles of the body are afterwards brought into action to compress it, so that usually in a few minutes its life is extinct, and its bones are broken. Deglutition then takes place—not, as has been alleged, after the prey has been licked and covered with saliva by the tongue, but accompanied with an extraordinary flow of saliva, which seems not only to serve fur lubrication, but to have the property of hastening the decomposition of annuld sub stances, and so to assist in making the prey more easy to be swallowed. It is always swallowed entire, and the process is sometimes rather a tedious one, and scents to require no small muscular effort; but the muscles of the serpent are capable of acting for this purpose, even at the neck, when that usually narrowest part of the body is dis tended to an enormous degree as the prey passes through it. The lower jaw is not sim ply articulated to the skull, but by the tnterventiori of other bones, a structure without which the prodigious dilatation of the throat would be impossible. The lungs consist
of two lobes, one much larger than the other, and at the extremity of the larger is au extremely capacious air-bag, which is supposed to serve for the necessary aeration of the blood whilst respiration is impeded in the process of deglutition.
The tail in all the boldne has great prehensile power. and its grasp of a tree round which it may be coiled is !tided by the opposing action of two claws, one on each side of the anus, which are really the representatives of the hinder limbs of the superior verte brate animals, and which, on dissection, are found to be connected not only with strong muscles, but with buttes entirely concealed within the serpent, one jointed to another, so as to make the character of a rudimentary limb very apparent. These serpents, being almost all inhabitants of watery places, often lie in wait for animals that come to drink; thus the largest of the American species, boa (euneetes) Tan rina —sometimes called ana coada, although anaconda scents to be originally, like B., the name of a serpent of the old world—is to be found where rivers or narrow lagoons are overshadowed by gloomy forests. Perhaps the want of sufficient supplies of ',voter, more than the greater cold of the climate, may account for the short time that specimens of the bolds brought to Europe have generally lived in confinement. . .
After a repast, these serpents spend a considerable time in a state of comparative torpidity—several weeks generally elapsing before they weken up to require a new sup. ply—and in this lethargic state they are easily killed. When they do waken up. the demands of appetite seem to be very urgent. Many of our readers must still rememixr the interest excited some years ago concerning a B. in the London zoological gardens. which, to the astonishment of its keepers, swallowed its rug; but this, after a trial of a week or two, it found indigestible, and the animal then gratified public curiosity by a reversal of the process of deglutition.
The head in the boidte is thick, yet somewhat elongated; the eyes are small; the body is thickest in the middle; the tail usually has a blunt The scales are num erous and nit ter small. The colors are various, and in many of the species rather bright and elegantly disposed. The true boas have the plates underneath the tail single, whilst iu the pythons they are double. 'Ile species to which the name boa constrictor Di appropriated is far from being one of the largest, seldom attaining a length of more than 12 feet. It is common in Surinam and Brazil, where its skin is used formilking boots and saddle-cloths. The name boa constrictor is, however, popularly extended to almost any of the species.—The number of species, whether in the genus or iu the family, is far from being well ascertained.
Boas are much infested by intestinal worms, which appear often to cause their death. The excrement of the I3.—the urine and faces being combined as in other rep tiles, and voided by a single vent—is a solid white substance, and consists mainly of unite of ammonia, accompanied by phosphate of lime (bone-earth). It is employed as an easy source of uric acid.