CH. IV] BATS OF NEW ZEALAND. 215 



where natural selection imposed no check upon unwieldy 

 bulk. 



Dr Dobson has pointed out the curious circumstance 

 that bats are not nearly so numerous in oceanic islands as 

 birds. From many considerations they ought to be ; 

 their nocturnal habits and the general nature of their 

 insect food are characters which would favour successful 

 colonisation. The reason apparently for their comparative 

 scarcity in islands which must have been stocked with 

 them from the nearest mainland is correlated with the 

 comparative rarity of flying objects. On another page 

 I direct attention to the fact that the insects of oceanic 

 islands are largely like the birds flightless. Now bats are 

 as a rule thoroughly aerial in their habits ; they seek their 

 prey upon the wing. This fact, thinks Dr Dobson, is 

 largely responsible for the poverty of Xew Zealand in 

 Chiroptera. 



Even in the British islands poor though their fauna 

 is there are eight times as many bats as in New Zealand. 

 One of the peculiar New Zealand bats, Mystacina tuber- 

 culata, "has the claws of the pollex and toes remarkably 

 elongated, very acutely pointed, and provided at the base 

 of each with a small talon projecting from its concave 

 surface near the base ; the wings are peculiarly folded so 

 as to occupy the least possible space ; and they and the 

 interfemoral membranes are preserved from injury by 

 being encased, when so folded, in a specially thickened 

 part of the wing and interfemoral membrane, analogous to 

 the thickened part of the anterior wings in Hemiptera, 



1 Ann. Mag. Nat. Hist. Sept. 1884. 



