XVI SKELETON OF BATS 
523 
more stronely developed 
in males than in females, 
and may perhaps be 
partly relegated to the 
category of secondary 
sexual characters. But 
it seems that they have 
also an important tactile 
function, and enable the 
creatures to fly without 
touching bodies which 
intrude themselves upon 
their way. The ears, 
too, are frequently very 
large, and it may be 
supposed that the sense 
of hearing is correspond- 
ingly acute. In _ the 
common Long-eared Bat 
of this country, the ears 
are not greatly inferior 
in length to the head 
and body of the animal 
combined. The ears are 
of every variety of shape, 
and offer characters 
which are valuable in 
the systematic arrange- 
ment of the members of 
the order. 
In the skull of Bats 
there is very rarely a 
complete separation be- 
tween the orbital and 
temporal fossae; the 
lachrymal duct is out- 
side the orbit. The 
tympanics are annular, 
and in a rudimentary 
condition. The centra 
fj 
" 
j 
(After de Blainville. ) 
x4, 
Pteropus jubatus. 
Skeleton of Flying Fox, 
255. 
FIa, 
