PEDIGREES— THE FOUNDERS OF THE HOUSE. 227 



of our hand. This third digit is in modern birds 

 very short, but in archseopteryx it was long and 

 armed with a strong claw. Now, these two 



Fig. 6. 

 Outline figures showing the two different types of 

 wing-membranes (w.) and their supports, contrasted 

 with the feathers of a bird which take the place of 

 membranes. The membrane of the bird has shrunk to 

 very slender proportions. 



