OBJECTIONS TO THE DARWINIAN THEORY 169 



united by a broad expanse of skin ; this fold of 

 skin, acting like a parachute, enables them to glide 

 through the air for a great distance from tree to 

 tree, and so escape their enemies. Here each step 

 is useful, and similar modifications are met with in 

 other animals. 



In GaleopitJiecus, the flying lemur of Borneo, the 

 skin fold extends from the neck to the hand, thence 

 to the foot and from this to the tail, and includes the 

 limbs with the elongated fingers. From this 

 Darwin suggested that the bat's wing could be 

 derived by elongation of the fingers. 



Further illustrations of the utility of imperfect 

 wines to arboreal animals or fish are found. The 

 flying frog of Borneo is a tree-frog with very long 

 and fully webbed toes, which enable it to take long 

 leaps in the air. The flying lizard [Draco volans) has 

 the skin of the flanks supported by ribs. In both 

 these cases there is no true power of flight, the 

 action being that of a parachute. Of flying fish 

 there are two chief groups, Dactylopterus (the 

 gurnard), and Exocoetus (the flying herring). In 

 both animals the pectoral fins are largely developed, 

 and in the gurnard are almost certainly moved like 

 wings. 



There is no difficulty in understanding these cases 

 as being acquired by Natural Selection, and the 

 bat's wing may be not such a serious difficulty 

 after all. 



Other Examples of Change of Function. — A good 

 instance of change of function is that of the Hyo- 

 mandibular gill-cleft. The presence of gill-slits in 



