ORGANIC EVOLUTION 



249 



parative anatomy) that the groups of birds and reptiles 

 would be found to be confluent in origin. Archeopteryx 

 is a bird possessed of teeth and a long tail, and other 

 structural characters more like to modern reptiles than to 

 modern birds. 



Among fossils there are occasionally found more or 

 less continuous series of forms, successively more prim- 

 itive in the successively older geologic formations. To 

 American palaeontology belongs the credit of discovery of 



FIG. 154. Archaeopteryx: a restoration (after Flower). 



