262 
ZOOLOGY. 
otherwise in so long a distance it would have little chance 
of alighting exactly upon the trunk. Its food consists 
chiefly of leaves. 
Order 4. Chiroptera (Bats). — The bats form a well-cir- 
cumscribed group of mammals, very distinct from any 
other, especially in the greatly modified fore-limbs, the ra- 
dius and ulna being united, and the second to the fifth 
metacarpal bones and phalanges being very long and slender, 
supporting a thin, leathery membrane or skin, extending 
to the hind legs, and wholly or partly enclosing the tail; 
the hind toes being, however, free, as when at rest or in 
the vegetarians when feeding, bats hang head downwards, 
holding on by their claws. The sternum is slightly keeled 
for the attachment of the muscles of flight. The mam- 
mary glands are pectoral. In other respects, especially the 
dentition, the bats resemble the Insectivora. The form of 
the teeth differs from the ordinary insectivorous bats in 
those which live on fruit. The vegetable-eating or fruit- 
ing bats have a superficial resemblance to the flying lemurs; 
and because their mammae are pectoral, have been placed 
next to the Primates. 
Bats live in caves and in the hollow of trees by day; all 
hibernate in the same situations, going into winter quar- 
ters in the autumn, and reappearing in the warm twilight 
of spring. Though the eyes are small, and the sight, so 
far as we know, deficient in keenness, they show wonderful 
skill in avoiding objects during their rapid flight. The ears 
are very large, and in the vampires the nose is adorned 
with sensitive, leaf-like growths of complicated form. Cer- 
tain bats, but not the true vampires, are known to enter 
houses and to suck the blood of sleeping persons, who 
awake to find their feet covered with blood. 
The largest bats are the fruit bats or flying foxes {Ptero- 
pus) of the East Indies, one species of which expands one 
and a half metres (nearly five feet) from tip to tip of the 
wings. They assemble in large flocks in the Moluccas to 
eat fruit, by day hanging by thousands on the trees. Our 
