. An introduction to the study of mammals living and extinct. Mammals. CHIROPTERA 649 and â with the nasal and labial appendages have been described when referring to the nervous system. It remains therefore to consider its relative development as part of the organs of flight. The extent and shape of the flying-membranes depend mainly on the form of the bones of the anterior extremities, and on the presence or absence of the tail. Certain modifications of these membranes, however, are met with which do not depend on the skeleton, but are related to the habits of the animals, and to the manner
. An introduction to the study of mammals living and extinct. Mammals. CHIROPTERA 649 and â with the nasal and labial appendages have been described when referring to the nervous system. It remains therefore to consider its relative development as part of the organs of flight. The extent and shape of the flying-membranes depend mainly on the form of the bones of the anterior extremities, and on the presence or absence of the tail. Certain modifications of these membranes, however, are met with which do not depend on the skeleton, but are related to the habits of the animals, and to the manner in which the wing is folded in repose. These membranes consist of the "antebrachial membrane," extending from the point of the shoulder along the humerus and more or less of the forearm to the base of the poUex, the metacarpal bone of which is partially or wholly included in it; the " wing-membrane," which is spread out between the greatly elongated fingers, and extends along the sides of the body to the posterior extremities, generally reaching to the feet; and the " interfemoral membrane," the most variable of all, which is supported between the extremity of the body, the legs, and the calcar (Fig. 297). The antebrachial and wing-membranes are most developed in those species fitted only for aerial locomotion, which when at rest hang with the body enveloped in the wings; but in the family Emhallonuridce, and especially in the subfamily Molossince (the species of which are the best fitted of all Bats for terrestrial progression), the antebrachial membrane is reduced to the smallest size, and is not developed along the forearm, leaving also the pollex quite free, and the wing-membrane is very narrow and folded in repose completely under the forearm. The relative development of the interfemoral membrane has been referred to above in describing the caudal vertebrae. Its small size in the frugivorous and sangui- vorous species, in which its presence w
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Keywords: ., bookauthorly, bookcentury1800, bookdecade1890, booksubjectmammals
