250 BA TS 



expansions of skin from the nose and adjacent parts of the face, forming what 

 is generally known as the ' ' nose-leaf. ' ' These folds of skin may be either compara- 

 tively 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 vari- 

 ous 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 

 finerea) 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 south- 

 ward 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 as far away from 



