THE BA TS. 33 



paratively recent age. Indeed, there is but little doubt that the creature 

 has been killed off within the human period, and in his history of Madagascar, 

 published in 1658, De Flacourt writes in the following terms of an animal 

 then inhabiting the island, which, if not actually the giant lemur, would 

 appear to have been a closely allied form. He writes that "the Tretretreire 

 or Tratratratra, is an animal of the size of a two-year-old calf, with a rounded 

 head and human-like face ; both fore and hind feet being like those of a 

 monkey. It has the hair wavy, the tail short, and ears like those of a 

 man. It resembled the Tanadie described by Ambroise Par^. It was seen 

 by the tank of Lipomani, in the neighbourhood of which was its abode. It 

 is a solitary creature, held in great terror by the natives, who flee when- 

 ever it comes in sight." With the exception of the rounded head and the size 

 (which is doubtless exaggerated), this description accords remarkably with 

 tJie giant lemur, and when tlie head was covered with fur, it is probable that 

 it would appear much less elongated than does the bare skull. 



ORDER II.— CHIROPTERA. 



The Bats. 



The second ordinal division of the Mammalia is that of the bats, or Chiroptera, 

 which is the one most easily defined of all, seeing that in no other members 

 of the class are the limbs similarly modified for the purposes of flight, while 

 it is in these animals alone among the class that the power of true flight is 

 found. By true flight is meant the capacity of sustaining the body in the 

 air for an indefinite period by the shortness of the wings ; this being markedly 

 different from the spurious flight of such creatures as flying-foxes, whose pro- 

 gress through the air is due merely to a leap from a height aided by para- 

 chute-like expansions of the skin of the limbs and the sides of the body. 



In the fore-limb or wing of a bat, the humerus or upper-arm bone is only 

 moderately elongated, but in the fore-arm the single bone corresponding to 

 the human radius has become greatly lengthened ; and this lengthening is 

 much more strongly marked in the case of the bones of the fingers, exclusive 

 of the thumb, all of which assume the form of very long and slender rods. 

 The thumb, which terminates in a hooked claw used for climbing and sus- 

 pension, remains free ; but the other four fingers are connected together by 

 the delicate, naked, leathery membrane of the wing, and mostly have neither 

 claws nor nails at the tip ; the longest of the whole five digits being the third 

 or middle finger. The membrane of the wing, or, as it is often called, pata- 

 gium, is continued up the arm and along the sides of the body to the hind- 

 legs, down which it extends ; while the two hind-legs are also connected by 

 another extension, which may embrace a considerable portion of the tail. 

 The membrane of the hind-legs is usually supported by a peculiar spur pro- 

 jecting from the foot ; but the toes, which are of normal proportions, remain 

 perfectly free from one another. Owing to the connection of the hind-limbs 

 with the membrane of the wings, the knee-joint is directed backwards instead 

 of forwards in the manner characteristic of all other terrestrial Mammals, and 

 this structure renders the movements of these animals on the ground so awk- 

 ward and shufiling. Bats always have very large and roomy chests, with 

 4 



