We are thus bound, in all honesty, to own up to our ape-like progenitors. But this is only a small portion of the wonderful tale told by Embryology. "Man is developed from an ovule about 125th of an inch in diameter, which differs in no respect from the ovules of other animals," [170] and, marvellous to relate, from that stage upwards the embryo is one continuous epitome of the history of man's evolution from lower forms of life. [171] Up to a certain point the germs, not only of all mammals, but of all vertebrate animals, fishes, reptiles, and birds, are scarcely distinguishable. A sceptic may convince himself by studying the plates given in Haeckel's The Evolution of Man, and especially plates ix. to xiv., where the embryos of various animals are compared. At the more advanced stage, where the embryo has already passed the reptilian form, we find that for a considerable time the line of development remains the same as that of other mammalia. The resemblance, for example, after the first four weeks' growth, between the embryo of a man and that of a dog is such that it is scarcely possible to distinguish the one from the other. Even at the age of eight weeks the embryo man is an animal with a tail, hardly to be distinguished from an embryo puppy. [172] After this period the embryo emerges from the general mammalian type into the special order of primates to which man belongs. Thus does the growth of the egg from which man springs compress into a few weeks the results of millions of years, and set before us the history of his development from fish-like and reptilian forms (which, as we have seen, p. 211, Mr. Gladstone deemed so contemptible and "fallen from greatness"), and of his more immediate descent from a hairy, tailed quadruped, the extinct common ancestor of man and monkey. As evolution proceeds the embryo rises up to man, and the differences specialising the human infant at its birth, such as the largeness and more complex convolutions of the brain, become more and more accentuated as its growth proceeds.