duck mole, the bird, the crocodile, the turtle, the lizard. They all have the same structure.
"Nor is this an isolated fact. From the fish was evolved the amphibian. From this came the lizard. From the lizard came the bird. The lizard has solid teeth in its mouth. The bird has no teeth in its beak. That is to say, it has none to-day. But it had when it was a lizard. Here, then we have an intermediate stage between the fish and the bird. We must expect that the bird embryo in the egg will show some trace of it. As a matter of fact, it does so. When we examine young parrots in the egg we find that they have teeth in their mouth before the bill is formed. When the fact was first discovered, the real intermediate form between the lizard and the bird was not known. It was afterwards discovered at Solenhofen in a fossil impression from the Jurassic period. This was the archeopteryx, which had feathers like a real bird and yet had teeth in its mouth like the lizard when it lived on earth. The instance is instructive in two ways. In the first place it shows that we were quite justified in drawing our conclusions as to the past from the bird's embryonic form, even if the true transitional form between the lizard and the bird were never
