CHIRON, or Cheiron, in Greek mythology, one of the Centaurs, the son of Cronus and Philyra, a sea nymph. He dwelt at the foot of Mount Pelion, and was famous for his wisdom and knowledge of the healing art. He offers a remarkable contrast to the other Centaurs in manners and character. Many of the most celebrated heroes of Greece were brought up and instructed by him (Apollodorus iii. 10. 13). Accidentally pierced by a poisoned arrow shot by Heracles, he renounced his immortality in favour of Prometheus, and was placed by Zeus among the stars as the constellation Sagittarius (Apollodorus ii. 5; Ovid, Fasti, v. 414). In a Pompeian wall-painting he is shown teaching Achilles to play the lyre.
See articles in Pauly-Wissowa’s Realencyclopädie and W.H. Roscher’s Lexikon der Mythologie; W. Mannhardt, Wald- und Feldkulte (1904).
CHIROPODIST (an invented word from Gr. χεἰρ, hand, and ποῦς, foot), properly one who treats the ailments of the hands and feet, or is consulted as to keeping them in good condition; the use of the word is now restricted, however, to the care of the toes, “manicurist” having been invented for the corresponding attentions to the fingers. The word was first introduced in 1785, by a “corncutter” in Davies Street, London.
CHIROPTERA (Greek for “hand-wings”), an order of mammals containing the bats, all of which are unique in the class in possessing the power of true flight, and have their fore-limbs specially modified for this purpose.
 | |
| Fig. 1.—Skeleton and Wing-Membranes of the Noctule Bat (Pipistrellus noctula). × 1/3 | |
c, Clavicle. h, Humerus. r, Radius. u, Ulna. d1, First digit. d2, d3, d4, d5, Other digits of the fore-limb supporting wm, the wing-membrane. m, m, Metacarpal bones. | ph1, First phalanx. ph2, Second phalanx. ph3, Third phalanx. am, Antebrachial membrane. f, Femur. t, Tibia. fb, Fibula. c, Calcar supporting im, the interfemoral membrane. pcb, Post-calcaneal lobe. |
The mammals comprised in this order are at once distinguished by the possession of true wings; this peculiarity being accompanied by other modifications of bodily structure having relation to aerial locomotion. Thus, in direct contrast to all other mammals, in which locomotion is chiefly effected by action from behind, and the hind-limbs consequently greatly preponderate in size over the fore, in the Chiroptera the fore-limbs, being the agents in propelling the body forward during flight, immensely exceed the short and weak hinder extremities. The thorax, giving origin to the great muscles which sustain flight, and containing the proportionately large lungs and heart, is remarkably capacious; and the ribs are flattened and close together; while the shoulder-girdle is greatly developed in comparison with the weak pelvis. The fore-arm (fig. 1) consists of a rudimentary ulna, a long curved radius, and a carpus of six bones supporting a thumb and four elongated fingers, between which, the sides of the body, and the hinder extremities a thin expansion of skin, the wing-membrane, is spread. The knee is directed backwards, owing to the rotation of the hind-limb, outwards by the wing-membrane; an elongated cartilaginous process (the calcar), rarely rudimentary or absent, arising from the inner side of the ankle-joint, is directed inwards, and supports part of the posterior margin of an accessory membrane of flight, extending from the tail or posterior extremity of the body to the hind-limbs, and known as the interfemoral membrane. The penis is pendent; the testes are abdominal or inguinal; the teats, usually two in number, thoracic; the uterus is simple or with more or less long cornua; the placenta discoidal and deciduate; and the smooth cerebral hemispheres do not extend backwards over the cerebellum. The teeth comprise incisors, canines, premolars and molars; and the dental formula never exceeds i. 2/3, c. 1/1, p. 3/8, m. 3/3; total 38. Despite the forward position of the teats, which is merely an adaptive feature, bats are evidently mammals of low organization, and are most nearly related to the Insectivora.
In consequence of the backward direction of the knee, a bat, when placed on the ground, rests on all fours, having the knees directed upwards, while the foot is rotated forwards and inwards on the ankle. Walking is thus a kind of shuffle; but, notwithstanding a general belief, bats can take wing from the walking posture.
The bones of the skeleton are characterized by their slenderness and the great size of the medullary canals in those of the extremities. The vertebral column is short, and the vertebrae differ but slightly in number and form throughout the group. The general number of dorso-lumbar vertebrae is 17, whereof 12 are dorsal; the cervical vertebrae are broad, but short. Except in fruit-bats (Pteropodidae), the vertebrae, from the third cervical backwards, are devoid of spinous processes. From the first dorsal to the last lumbar the vertebral column forms a single curve, most pronounced in the lumbar region. The bodies of the vertebrae are but slightly movable on each other, and in old individuals become partially welded. The caudal vertebrae are cylindrical bones without processes; their number and length varying in allied species. The development of these vertebrae is correlated with habits, the long tail in the insectivorous species supporting and controlling the position of the interfemoral membrane which aids bats in their doubling motions when in pursuit of insects by acting as a rudder, and assists them in the capture of the larger insects. In the fruit-bats this is not required, and the tail is rudimentary or absent. In all bats the presternum has a prominent keel for the attachment of the great pectoral muscles.