which represent the skeletons of an Orang, a Chimpanzee, a Gorilla, and
you find you have no trouble in identifying the bones throughout; and
lastly turn to the end of the series, the diagram representing a man's
skeleton, and still you find no great structural feature essentially
altered. There are the same bones in the same relations. From the
Horse we pass on and on, with gradual steps, until we arrive at last at
the highest known forms. On the other hand, take the other line of
diagrams, and pass from the Horse downwards in the scale to this fish;
and still, though the modifications are vastly greater, the essential
framework of the organization remains unchanged. Here, for instance,
is a Porpoise: here is its strong backbone, with the cavity running
through it, which contains the spinal cord; here are the ribs, here the
shoulder blade; here is the little short upper-arm bone, here are the
two forearm bones, the wrist-bone, and the finger-bones.

Strange, is it not, that the Porpoise should have in this queer-
looking affair--its flapper (as it is called), the same fundamental
elements as the fore-leg of the Horse or the Dog, or the Ape or Man;
and here you will notice a very curious thing,--the hinder limbs are
absent. Now, let us make another jump. Let us go to the Codfish:
here you see is the forearm, in this large pectoral fin--carrying your
mind's eye onward from the flapper of the Porpoise. And here you have
the hinder limbs restored in the shape of these ventral fins. If I
were to make a transverse section of this, I should find just the same
organs that we have before noticed. So that, you see, there comes out
this strange conclusion as the result of our investigations, that the
Horse, when examined and compared with other animals, is found by no
means to stand alone in nature; but that there are an enormous number
of other creatures which have backbones, ribs, and legs, and other
parts arranged in the same general manner, and in all their formation