“On descrying the prey,” says Tennent, “they advance rapidly by semi-circular strides, fixing one end firmly and arching the other forward until by successive advances they can lay hold of the traveller’s foot, when they disengage from the ground and ascend his dress in search of an aperture. The wound they make is so skillfully punctured that the first intimation is the trickling of blood or the chill feeling of the worm as it begins to land heavily on the skin.” These worms, hirudinae or leeches, are remotely related to earthworms with a quite similar internal structure, but highly specialized for an exclusive diet of warm blood which they take from any mammal that comes within reach. The blood-sucking species—not all species are this type—have triangular mouths with extremely sharp chitinous [of the same material as the shells of insects] teeth. The bite, so rapidly and skillfully administered that it seldom is felt, has been described as resembling the movement of a circular saw. Haemadipoa, the Ceylon species, described by Tennent, reportedly has five pairs of keen eyes and as many as 100 body segments. All the blood eaters have two suckers, one on the front and one on the rear of the body, by means of which they cling to their victims. All have the ability to contract the body to a plump, pear-like form and extend it to a wormlike form. The green worms are as much of a terror as ever to travelers in Asian jungles. A species akin to that of the Kandy defense armies guards the thickly forested approaches to the Himalayas in Nepal It is described by Dr. George Moore, chief of the United Nations medical mission to Nepal: “These leeches, little segmented worms about two inches long, were particularly provoking and troublesome until our team reached an altitude of 14,000 feet. Along the trails, on each ledge leading to the pass, leeches would lie in the shade and moisture until nearby footsteps vibrated their sense organs. Then they would inch from rock to rock at incredible speed, traveling their entire length toward the sound in about a second and then stopping to perch on the rock with their front ends sticking in the air. Immediately they touched a human body they would fasten themselves to it and search for warm skin. Often they would drop from trees. They could penetrate eyelets of shoes and pores of socks by lengthening the entire body. Huge clots of blood would be found on the skin where the greedy worms had fattened themselves to a fragile bursting point.”