the sexual union of different species, so as to produce individuals having a union of the different organisms, or a resultant of a third organism of a different type from any that had preceded it. Is it, for example, from mere taste or moral feeling that such occurrences as the sexual union between man and beast have not been known to have produced a third and different animal? We know that it is because the Almighty has "fixed his canon" against such a union in the case of man and in the cases of all the other distinct animal organisms; and to find this canon we do not need to go to Scripture or revelation, although we may find it there also. We are remitted, therefore, to indirect evidence, and in considering this evidence we have to note that we have nothing but an imaginary pedigree, or one hypothetically constructed, to which to apply it. In tracing the pedigree of an individual animal, we have a certain number of known connections of life with life; and where it becomes necessary to bridge over a break in the connection so as to carry the line back to an earlier ancestor, we may perhaps apply the collateral evidence of family or race resemblance to assist in making the connection with that particular ancestor a reasonably safe deduction. But in the case of the hypothetical pedigree which supposes the human race to have been evolved from a single cell through successive organisms rising higher and higher in the scale of being, we have no known connections of lives with lives to which to apply the collateral proofs. The collateral proofs are not auxiliary evidence; they are the sole evidence; and unless they are such as to exclude every other reasonable explanation of the phenomena which they exhibit excepting that of the supposed evolution, they can not be said to satisfy the rules of rational belief in the hypothesis to which we apply them.