.250 BATS. 



adjacent parts of the face, forming what is generally known as the " nose-leaf." 

 These folds of skin may be either comparative!}^ small and simple, or so large as to 

 form a kind of mask, communicating a most extraordinary physiognomy to the 

 bats in which they occur. The various membranes forming these nose-leaves are 

 always fringed with long and fine hairs, which evidently correspond to the 

 *' whiskers " of the cat : and we may accordingly regard these nose-leaves merely 

 as an excessive development of the cat's whiskers, accompanied by leaf -like 

 growths from the skin of the nose. It has been observed by Dr. Dobson our 

 great authority on bats that those species which are without nose-leaves are in 

 the habit of flying at dawn or twilight, while the leaf-nosed kinds are more 

 strictly nocturnal, and are thus much less frequently shot when on the wing. 

 The fruit-eating bats, whose habits are very different from the other members of 

 the order, never have these nose-leaves, and their ears are small and unprovided 

 with a tragus; there being no necessity for the extreme delicacy of tactile 

 perception required in the other groups. 



When on the wing, the ordinary insectivorous bats utter a short, 



sharp squeak of such an extremely high pitch that to many persons 

 it is quite inaudible, although to others, whose ears are attuned to the reception of 

 such high-pitched tones, these cries are of piercing intensity. 



The insect-eating species of bats inhabiting the temperate regions, 



being dependent for their nourishment upon a full supply of insects, 

 must in winter either migrate to warmer regions, or hibernate. In our own 

 country all the species hibernate, and do not appear to migrate at all : and it is 

 probable that this hibernating habit also holds good for the whole of the European 

 bats. It seems, however, that at least one North American species the Vespertilio 

 borealis migrates to a certain extent during the summer, not visiting the more 

 northerly portions of its habitat till August, when the long intense twilights, 

 which would be unsuitable to its habits, have ceased. In Canada, moreover, Dr. 

 Hart Merriam is of opinion that at least two species of bats regularly perform 

 extensive migrations in order to avoid the intense cold of the northern winter. 

 This eloquent writer observes that " all North American bats, except when their 

 habits have been modified by proximity to man, may be classed as cave-dwelling or 

 tree-dwelling, according to the places in which they spend the day. As a rule, the 

 cave-dwelling species live in large colonies, while the tree-dwelling live singly or in 

 small companies. Now, it is well known that the temperature in caves, even in 

 high latitudes, is little affected by the external atmosphere, but remains nearly 

 uniform throughout the year; while in holes in trees the temperature is about the 

 same as that of the surrounding air. Hence, animals inhabiting caves can pass the 

 winter much farther north than species living in hollow trees. The hoary bat 

 (Atalapha cinerea) is a tree-dwelling species, and its home is in the Canadian 

 fauna, from the Adirondack Mountains northward. Therefore, on purely theoretical 

 grounds, it should be expected to migrate." Now, specimens of this bat have been 

 not unfrequently observed in the autumn and winter from localities so far to the 

 southward of its usual habitat, that there would seem to be no longer any reasonable 

 doubt as to its being truly migratory. It has, indeed, been found so far away from 

 its ordinary summer haunts as the Bermudas, where Mr. J. M. Jones states that it 



