2 5° 



BATS. 



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



These folds of skin may lie either comparatively 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 iine hairs, which evidently correspond to the 



•' whi.skers " of the cat ; and we may accorchngh' 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 ordinarv insectivorous bats utter a shoii,, 

 Cry. . 



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 Xorth American species — the VespertiUo 



horealis — migrates to a certain extent during the summer, not visiting the moi'e 



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 micrrations 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 proximitj' to man, may be classed as cave-dwelling or 



ivee-dwclliinj, according to the places in which they spend the day. As a rule, the 



cave-dwelling species li\e 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 atfected 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 hoaiw 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 



