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Show 1906.] MR. R. SHELFORD ON " FLYING" SNAKES. 229 the latter by virtue of a pronounced concave surface is buoyed up a certain extent, and very frequently its fall terminates in a slight upward swoop, so that it reaches the ground with but little violence of impact. The same holds good, as I believe, for those snakes that can convert their cylindrical shape into the semblance of a split bamboo. A specimen of Chrysopelea ornata was taken to a height of fifteen to twenty feet and allowed to fall several times; after one or two false starts the snake was felt to glide from the experimenter's hands, straightening itself out and hollowing in the ventral surface as it moved, and it fell not in a direct line to the ground, but at an angle, the body being kept rigid the whole time. The height from which the snake fell was not great enough for it to be possible to determine with any accuracy whether it fell more slowly than when it fell in irregular coils, but it certainly appeared to be so. If the snake was thrown up into the air, it seemed unable to straighten itself out; it had to be launched, so to speak, from the hands in order to induce it to assume the rigid position; and no doubt in its natural haunts the snake prepares itself for a parachute flight by gliding with some force from off a branch, and does not fall in the casual manner of such a species as Tropidonotus maculatus. Text-fig. 57. Diagrammatic transverse sections of the bod}' of Chrysopelea ornata. A, in the normal condition ; B, during " flight." It was not until 1904 that another Dyak collector brought me a specimen of Dendrophis pictus, with the assertion that he had witnessed its "flight" from a tree; the story of this quite independent witness was to the effect that he had seen the snake shoot out from a tree and fall at an oblique angle to the ground, its body being held straight during the fall. This species also has the hinged ventral scales characteristic of the genus Chrysopelea, but whereas Chrysopelea belongs to the Opisthoglyphous group of Colubrines, Dendrophis is one of the Aglypha; it is larger than either of the Chrysopelece. Experiments that were carried out with this species did not prove so conclusive as those with C. ornata, but it was observed that if the snake was held up by the tip of the tail the ventral surface of the body became concave 16* |