260 
NATURAL HISTORY. 
structure j biped, quadruped; walking, but not with feet; flying, but not with feathers; seeing without 
light, in the light, blind ; it uses light beyond the light, but wants light in the light ; a bird with 
teeth, without a beak, with teats, with milk, bearing its young even when flying.” Can it be wondered 
at that such a creature should be a puzzle 1 
Nevertheless, some ancient writers seem to have entertained clearer notions on the subject, such 
as Macrobius, who maintained that as the Bat walked like a quadruped it ought to be classed with 
quadrupeds, for which he is blamed by J onston, who speaks with approval of Plato’s opinion, according 
to wliich this unfortunate animal is neither bird nor beast, an opinion which partially prevailed to a 
lather late date. Throughout the Middle Ages, however, the general opinion even of professed natural- 
ists was that Bats were birds ; and we find this notion prevailing down to the time of Aldrovandus, in 
the latter part of the sixteenth century, and of J onston, whose gigantic compilation was published 
in 16-37. It is a question whether this notion that Bats are birds has even yet been entirely dis- 
pelled in the popular mind, and no doubt many people still regard them as birds, because they 
SKELETON OF THE MOUSE-COLOURED BAT (VESPERTILIO MURINUS.) (From De Blainville). 
a, humerus; b, shoulder-blade; c, collar-bone; d, fore-arm (radius, with the ulna at the elbow); e, wrist-bones (carpal-bones) • 
/, thumb ; g g, metacarpal bones ; s s, breast-bone (sternum) ; p, pelvis ; i i , heel-simr. 
can fly, just as Whales and Seals are considered fishes, because they swim, and Centipedes and 
Scoipions reptiles, because they crawl. John Bay, the father of modern zoology, writing in 1683, was 
the first to refer the Bats to their true position among the Mammalia (animals which suckle their 
3 oun g)j and in this course lie was followed by Linn as us, who actually placed these puzzles of former 
naturalists in his highest order of Mammals, the Primates, along with man and the Apes. The 
position assigned to them by Linnaeus in the series of animals they have virtually retained in nearly 
all systems to the present day. 
By all modem zoologists the Chiroptera have been regarded as a distinct order of the Mammalia, 
characterised especially by tlieir possession of the power of flight, and the consequent modification of 
the structure of their fore limbs, which is indicated in the name given to the group (Chiroptera hand- 
wings). They are, in fact, the only true flying Mammals, and, indeed, the only truly flying Vertebrates 
except birds, for the so-called flying Squirrels, flying Lemurs, and flying Opossums are only furnished 
with a broad fold of skin on each side of the body, wliich, when expanded by the spreading of the l im bs, 
acts as a sort of parachute to sustain them for a time in the air. This is also the case with the flying 
Dragons, although in them the membrane is stiffened by means of a portion of the ribs ; and even in 
the flying fishes, in which the organs of aerial locomotion are formed by the fore-limbs, these merely 
sustain the fish in the air for a time by the increased surface they give it, but do not serve as real 
wings, like those of Bats and birds. 
There is, however, an important difference in the structure of the wing in the Bats and birds. 
