152 1 GUIDE TO THE 
and hence this order of animals is known as the hand- 
winged, or Chiroptera. The first finger or thumb is short, 
separate from the others, and provided with a claw, the 
other fingers being clawless with the exception of the 
second which occasionally has one. The wing-membrane 
is not merely confined to the hand, but extends between 
the fore-arm and the side of the animal to the ankle, 
and another membrane exists between the hind-legs some¬ 
times enclosing the whole of the tail in those species in 
which a tail is present. The wing-membrane is an ex¬ 
tremely sensitive stucture, and it is to this property in the 
wing that the bat chiefly owes its remarkable facility of 
flying with impunity through the darkest passages and 
caverns, away from all light whatever. But some bats are 
furnished with other highly sensitive organs grouped around 
the nose as leafy appendages, and by little face-tubercles 
bearing stiff hair or vibrissa. The correctness of their flight 
is also doubtless much assisted by their ears which are 
generally very large and frequently united together over the 
forehead, and, in some species, the ears equal the length of 
the body, and they are extremely sensitive and mobile. 
Their eyes are very small and their vision seems to be sup¬ 
plemented by the organs just indicated, because when a bat 
has been effectually blinded, by the complete destruction of 
its eyes, it has been found that it is still able to fly about 
freely without striking against objects. 
Bats are divided into two great groups, the Frugivorous 
and the Insectivorous Bats, the former containing the giants 
of this order, and hence Dr. Dobson has called them the 
Megachiroptera , the other section being the Micro chiroptera. 
The Flying-fox in this compartment is an example 
of a fruit-eating bat which is frequently to be seen in 
