THE EVIDENCE FROM MISSING LINKS. 159 



joints, each of which supported a pair of quill feathers. Then, 

 secondly, no ploughshare-bone (Fig. 76 d) was developed. The 

 fingers, united by bony union in existing birds, were free and reptile- 

 like in Archseopteryx, and, whatever their number may have been, it 

 is certain that these fingers were provided with reptile-like claws, 

 such as are seen in no living bird. 



Such were the details of Archaeopteryx structure at hand till 

 within the last three years or so. In 1879 Professor Carl Vogt made 

 a communication concerning a fresh specimen of this ancient bird, 

 found in the same deposits which afforded the previous specimen. 

 The new specimen was singularly complete ; and its wings were 

 unfolded, as if death and fossilisation had overtaken it in the act of 

 flight. Its examination revealed certain startling features, which only 

 serve to confirm in an unmistakable manner the thoroughly " inter- 

 mediate " nature of this animal. Its upper jaw bore two small conical 

 teeth ; the breast-bone is " reduced to zero ; " and whilst its arm- 

 bones " present no features peculiar to reptiles or to birds," its hand 

 can be compared neither to that of a bird nor to that of a ptero- 

 dactyl, but to that of a three-toed lizard. " If the feathers had not 

 been preserved," says Vogt, "no one could have ever suspected 

 that, from the examination of the skeleton alone of Archaopteryx, 

 this animal was furnished with wings when alive." Head, neck, chest 

 and ribs, tail, shoulder-girdle, and arm or wing, are all built on a rep- 

 tilian type ; the haunch is more reptilian than bird-like ; but the hind 

 limbs are those of a bird. The reptile characters unquestionably 

 predominate in the skeleton, just as the bird-characters come to the 

 front in the feathers. 



Professor Vogt strenuously asserts that a study of Archaopteryx 

 shows that it is neither bird nor reptile, but that it is a decided 

 " link " betwixt the two classes. It is a bird by its feathers and 

 hind limbs; it is a r reptile by the rest of its structure ; and it is, 

 moreover, a bird only in so far as we regard its type as having 

 emerged from a reptilian stock. The birds to be presently described 

 from the American Chalk are later developments. As such, they 

 are nearer the birds of to-day; but they retain the reptilian 

 teeth, whilst the rest of their organisation has been evolved along 

 the lines of bird- structure. Professor Vogt further insists on 

 the fact that the adaptation to flight is not necessarily combined 

 with an erect position, since the extinct pterodactyls and the living 

 bats illustrate cases in which that position was and is not maintained. 

 The bird-like hind feet of the Archaopteryx must be viewed as 

 having been independent of flight, and as related to the possibility of 

 sustaining the body on the hinder feet alone. In other words, we 

 are not specially entitled to concern ourselves with the question of 

 flight in this ancient animal ; and the consideration is worth attention 



