It is doubtless an interesting speculation to go back in imagination to a period to be counted by any number of millions of years, or covered by an immeasurable lapse of time, and to conceive of slowly-moving causes by which the present or the past inhabitants of this globe became developed out of some primordial type, through successive generations, resulting in different species, which became final products and distinct organisms. But what the imagination can do in the formation of a theory when acting upon a certain range of facts is, as a matter of belief, to be tested by the inquiry whether the weight of evidence shows that theory to be, in a supreme degree, a probable truth, when compared with any other hypothesis. It is in this way that I propose to examine and test the Darwinian pedigree of man. The whole of Mr. Darwin's theory of the descent of man as an animal consists in assigning to him a certain pedigree, which traces his organism through a long series of other animals back to the lowest and crudest form of animal life; and it must be remembered that this mode of accounting for the origin of man of necessity supposes an unbroken connection of lives with lives, back through the whole series of organisms which constitute the pedigree, and that, according to the Darwinian theory, there was no aboriginal creation of any of these organisms, save the very first and lowest form with which the series commences. Not only must this connection of lives with lives be shown, but the theory must be able to show how it has come about that there are now distinct species of animals which never reproduce any type but their own.