Page:The New International Encyclopædia 1st ed. v. 02.djvu/670

BAT. thence stretches to the hind-leg (leaving the foot free), and in most families to, or nearly to, the end of the tail; but its relative size and shape vary. Stretching this great membrane and beating the air with it, the bat flies with more than the agility of a bird, thongh more slowly, and when it rests it folds the membrane somewhat like a fan against its sides, or wraps it about its body like a protecting mantle.

Scnse-Orgaiis. — The brain and nervous system of bats are comparatively low in organization, but their sensory faculties are remarkably developed in adaptation to their crepuscular and nocturnal habits. 'As blind as a bat,' is a mistaken simile. All have etficient eyes, those of the Oriental fruit-eating sorts being of a size natural to their fox-like countenances. In our more familiar insect-eating species they are likely to be small, bead-like, and nearly hidden in the very soft fur with which the.se animals are clothed; the old English and C4erraan names •flitting mice,' were not Ijad ones. The senses of smell and taste are probably well developed. The sense of hearing is no doubt exceedingly acute and largely de- pended upon. All bats have prominent and very mobile ears, and in many of the insect-eaters, the external ear expands in an enormous membrane, sometimes many times larger than the whole face, supplemented by appendages, ribl)ed, crinkled, and otherwise modified, and in some forms able to be folded down out of the way of harm. These expansive ears are evidently of more utility than simply to catch waves of sound, and are related to the extraordinary sense of touch, whieli perhaps is carried to a higher de- gree of delicacy in these than in any other ani- mals. In addition to them a large section of the order possesses 'nose-leaves' — more or less wrinkled and complicated upright growths of thin skin from the end of the nose, which often give to the face a most grotesque appearance. Two of the most extraordinary examples are shown on the accompanying plate — the flower- nosed bat (Fig. 7), a native of the Solomon Islands: and Blainville's chin-leafed bat (Fig. 5) of South America. On the other hand, in some species such appendages are wholly absent, as in the ugly naked bat ( Fig. 3 ) of the Malay coun- tries.

All these membranes, as well as those of the wings, are filled with blood-vessels and numerous ramifications of fine nerves, which take the form •elsewhere seen in especially sensitive surfaces, and they are regarded as apprising the creature, in a way not fully understood, of the nearness of obstacles, and giving other useful information. This was illustrated by the celebrated experi- ments of Spallanzani, about 177;). He blinded bats with arnish, and let them fly in a chamber filled with stretched and dangling strings. These and other obstacles they avoided ; they tunied corners, foiuid holes for escape or concealment, and behaved as though eyesight were unneces- sary; stoppage of the ears, however, caused them sorne embarrassment. (Xher obsen-ations have confirmed their ability, apparently through ex- treme sensitiveness of the pX]iosed membranes, to sense objects without sight or actual touch.

DiRTKTBUTlON. liats are distributed in all parts of the world, and, as might be expected from their powers of flight, inhabit many re- mote islands, such as Bernuida and New Zea- land — the only indigenous manunals of the lat- ter being two species of bats. They are absent, however, from the coldest parts of the world, and are most numerous in the Eastei-n tropics, to which some groups are confined : in fact, the race is characteristically tropical. In rather cold climates, such as that of Canada, some species have acquired a habit of migration, going south to some extent in the autumn, as the northern winters are too long to be survived in a state of uninterrupted hibernation. This seems to be the case, according to ilerriam, with two speei^g of North American bats, both of which habitu- ally rest in trees instead of in the warmer re- cesses of eaves. The number of kinds of bats is so great that about 450 species are now recog- nized ; and the enormous companies of certain species that congregate in favoraijle places are unrivaled elsewhere among gregarious mammals, and recall the great flocks of sea-birds to be seen in certain nesting localities.

AxcESTRY. Few fossil remains of bats are known. In the Upper Eocene deposits of Aix, France, has' been found a well-develojied bat's wing, and in other portions of the Tertiary de- posits of the same country have been found skulls of species that very closely resemble those of modern forms. In North America their re- mains are known in fragmentary condition from the Eocene, Miocene, and Post-Tertiary deposits, and in South America they have been recog^nized in the cave deposits of Brazil. All these difl'er little from living genera.

Ci,ASSiFiCATio>r AXD Habits. Bats are classi- fied as an order, divisible into two sections, Megaeheiroptera and Microcheiroptera.

Aleciacheiroptera. — These are lowest in rank, and include the large-sized fruit-eating species, mainly of the Oriental tropics. The lowest in rank are the fox-))ats or "flying-foxes' of the family Pteropodid:i?. They are described under the titles Fox-Bat and Feuit-Bat.

Microcheiroptera. — In this division are found all other bats — the ordinary bats of temperate climates, as well as nuiny tropical ones — which agree in being of small size, in living, as a rule, upon insects to which their dentition is suited, and in having more or less of a tail enveloped in an interfemoral membrane. The first family is that of the Horseshoe Bats (Rhinohiphidip), whose snouts bear such appendages as have been described, differing according to species. They are scattered throughout Southern Asia, where many species are Avell known, and a fe^n' extend into Europe and the British Isles. Most of them are of the ordinary brown color, but an Austra- lian species is bright orange in the male and yellow in the female. A family having still more prominent growths about the nose and ears is that of the Leaf-nosed Bats proper ( Nycteridie ). Two genera inhabit Eastern Asia, represented by the lyre-bat {MciindeDiKt h/ra), whose vast ears are joined together above the head, and which sometimes attacks and kills other bats and small uiammals, sucking their blood. In the next family, Vespertilionidw. are grouped the 'true,' or familiar, small, naked-faced bats of all coun- tries. They feed almost exclusively on insects, which they capture in flight, and which their sharp and numerous teeth are fitted to hold and crusli ; they sjiend the hours of daylight in eaves, ruins, hollow trees, garrets, and similar hiding-places, sometimes resorting to caverns in vast numbers, and so continuouslv that thick