THE "GENERAL MORPHOLOGY" 223 



to man himself must also have done so. Hence 

 the law must have transmitted even to ourselves 

 this ancestral form of the gill-breathing fish. 



What a mad idea, many will say; that man 

 should at one time be a tadpole like the frog! 

 And yet — there's no help in prayer, as FalstafE 

 said — even the human germ or embryo passes 

 through a stage in the womb at which it shows 

 the outline of gills on the throat just like a fish. 

 It is the same with the dog, the horse, the 

 kangaroo, the 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, on Darwinian principles, 

 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 Qgg we 

 find that they have teeth in their mouths 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 



