place of the series of quill-feathers found in the wing of the 

 bird. In the second it wiU be found that this membrane is 

 stretched between a series of long and very slender bony rods. 

 These are excessively attenuated fingers-. And if the hinder 

 border of the wing-membrane be traced inwards it will be 

 found to be attached to the hind limb. In some species it 

 wUI be found that this membrane passes backwards beyond 

 the leg to attach itself to the tail. Here, then, is a wing as 

 efficient for its purpose as that of a bird, but constructed on a 

 totally different plan. 



Ages ago, before even the birds or the beasts had appeared 

 on the earth, the winged dragons, which the Men of Science 

 call Pterodactyles, held the proud position of being, not only 

 the first, but the only creatures blessed with a backbone that 

 could fly. Their wings resembled those of the bats, but 

 differed in this, that instead of the wing-membrane being 

 stretched between aU the fingers, leaving only the thumb 

 free, it was attached only to the fifth finger, leaving the 

 remaining fingers free, and these were reduced to mere 

 vestiges. As with the birds, the breast-bone was very broad 

 and was furnished with a keel, whUe in the bats it takes the 

 form of a joined rod, down which no more than a slight keel 

 is ever developed. 



But millions of years before the Flying-dragons, birds, 

 and bats came into being, the stupendous problem of flight 



8 



