INTRODUCTION 



ON THE CLASS AVES, OR BIRDS IN GENERAL 



Birds are distinguished from all other living 

 creatures by their covering of feathers. They are 

 moreover bipeds, and have beaks, wings, and tails ; but 

 these features are not peculiar to them, while the power 

 of song and the method of reproduction by eggs are also 

 held in common with other animals. Again, ability 

 to fly, in the true sense of the term, is a possession of 

 most species at the present day, but Palaeontology 

 teaches us that of old there were flying Lizards, and 

 even now we have flying mammals in the shape of 

 Bats. None of these points therefore, with the excep- 

 tion of the first, are unfailing characteristics of the 

 Class Aves. 



There is no doubt that the ancestors of our birds 

 bore a remarkable resemblance to reptiles, and that, 

 if they did not actually spring from them, as is now the 

 orthodox belief, both must have certainly arisen from a 

 common origin, that is, from some creatures combining 

 in themselves those points which the two classes have in 

 common. This is the more evident when we consider 

 the earliest known fossil bird, now termed Archceo- 

 pteryx lithographica, which was discovered at Solenhofen 

 in the kingdom of Bavaria. It was about the size of 

 a Rook, and was in all probability a tree-loving species. 



