ruis. 13 



.mu)unt of carlh movcmciUs which it must ncccssaiily have 

 lilcd. Although we arc averse to calling in such movements 

 locossarily, wc confess that, in our opinion, his theory does 

 ; .iccount for the poverty of the Mammalian fliunaof Ireland 

 J. . compared with that of the rest of Britain in the perfect 

 nnnncr in which that of Mr. Wallace does; and until this 

 ,s doju* we prefer to incline towards the latter, which, it must 

 oe remembered, is to a consiilerahle extent supported by the 

 submerged forests and ancient deserted river-channels of Eng- 

 land. 



Whether, however, the one theory or the other of the re- 

 poiuilation of England be adopted, wc have to remember that 

 the present impoverished Mammalian fiiuna of Britain, as com- 

 pared with the Continent, is due to the direct or indirect 

 action of the Glacial period, the elTects of which have been so 

 far reaching both on inanimate and aniuKite nature in the 

 Northern Hemisphere. 



THE BATS. ORDER CHIROPTERA. 



VlxQ special modification of the bones of the fore-limb for 

 the \>urpose of flight, coupled with the presence of a leathery 

 llying-u\eu\brane extending from the front of the fore-limb, 

 com\ecting together the toes, or lingei*s, of the same, then 

 joinii\g the hind-limbs, and likewise connecting together the 

 two latter, with or without the intervention of the tail, at once 

 serves to distinguish sharply the Bats from all other members 

 of the Mamtnaliai\ class. They are likewise the only Mammals 

 endowed with the power of true flight, like birds; the long 

 flying leaps of the Flying Squirrels and the Flying Phalangers 

 IkMUg nothing more than a prolongation of an ordinary leap by 

 the aid of a pamchutc like c.xjvxnsion of the skin of the flanks, 

 without any siKcial modification or elongation of the bones of 

 tlie lore limbs. 



Kcfcriii\g in some detail to the structure of the fiaire^Hmb, 



