PYTHON, a genus of snakes of the family Boidae. The snakes of this genus are very large and are found throughout the tropical regions of the Old World; they are distinguishable from the boas, with which they are often confused, by the presence of an extra bone in the skull above the eye, the supra-orbital. All the members of the genus possess long powerful teeth, but there is no poison apparatus. Killing is effected by constriction; coil after coil is thrown round the victim and these are slowly tightened. All snakes of whatever size are extraordinarily muscu lar so that the pressure exerted by a large python when con stricting must be terrific; usually all the bones of the prey are broken and the whole animal is crushed into the shape of a sausage. This is then swallowed, head first, the head and body of the snake being literally drawn over the victim's body by the alternate forward motions of the right and left halves of the jaws; it is during this swallowing process that the large teeth are called into play, those of one side being dug in and giving a grip whilst the other side is pushed forwards. During the swallowing proc ess much saliva is secreted and should the prey be disgorged, as it sometimes is if the snake is disturbed or frightened, it will be found to be covered with this secretion; this probably accounts for the origin of the fable that pythons cover their prey with saliva before swallowing it.
There is little doubt that a large python would be physically strong enough to kill almost any large mammal, but the stories of their killing and eating cattle and horses cannot be credited; the prey must be swallowed whole and the mouth of even the largest specimens, wonderfully distensible though it is, could not be stretched to accommodate anything much larger than a small pig. Most species are semi-arboreal and prefer the neighbour hood of water, in which they often lie and soak. Reproduction is by means of leathery-shelled, oval eggs, of which there may be a hundred or more in a clutch; they are laid in a heap round which the mother coils herself and it has been found that the temperature of a female under such circumstances rises above that of the surrounding air so that there is, apparently, true incubation.
The largest species is the reticulated python (P. reticulates) of the Indo-Chinese and Malayan regions; which may attain a length of 3o ft. Other well-known species are the Indian python (P. molurus) of India and Ceylon, the rock python (P. sebae) of tropical and South Africa, the West African python (P. regius) and the Australian carpet snake (P. spilotes). (H. W. P.)