ANCIENT BIRDS 215 
its curiously “mixed” characters. It is certainly one of the most 
anomalous types of ancient life that has ever been discovered. 
Palzontologists are now agreed that it was a bird; for it had 
feathers and claws, as birds have. But what can we say to 
a bird with teeth in its jaws, and with a long, lizard-like tail 
such as reptiles have now, except that this tail was provided with 
feathers attached in a very peculiar way, contrary to all bird’s 
tails of the present day? A naturalist acquainted only with the 
avian life of to-day, would certainly say that it upsets nearly all 
his ideas of what a bird ought to be; but that only shows how 
useless it is (as we have previously pointed out, see pp. 105 and 
199) to lay down rules for Nature. Its vertebrae are bi-con- 
cave, like those of fishes and some extinct Saurians. Another 
very reptilian feature is the presence of “sclerotic plates” in the 
eye. A pair of feathers sprang from each joint in the tail, which 
is quite a different arrangement to that in the tail of living birds. 
The leg-bone and foot are similar to that of modern perching 
birds, but then we have seen that some of the Dinosaurs, such 
as the little Compsognathus, had very bird-like feet. The wing 
shows three free digits or fingers. In form and position these 
three finger bones are just what may be seen in some young 
birds of to-day. It has been claimed by some that the fore limb 
of Archeopteryx is reptilian, but Mr. W. P. Pycraft has shown 
that it is more bird-like than some people thought, for it much 
resembles that of a young chick, and still more that of a primitive 
bird known as Opisthocomus. Another point, established by Marsh, 
is that the bones of the pelvis are separate—not united, as in 
modern birds. In the London specimen (where the skull is lost) 
there remains a cast of what is supposed (perhaps wrongly) to be 
the brain cavity. Were it not for the feathers, perhaps no 
one would at first have thought of calling it a bird. It combines 
