the weakening of the latter might mean the (relative) strengthening of the former. But such is not the case: the theologian, as a theologian, can only say, "God made the world"; science alone can undertake to show how the work was accomplished, i. e., through what successive stages and genetic connections. If, then, the evidence for Darwinism, or for evolution generally, is not complete, all we can do is to wait until it is complete, or until some physical theory of things is established on solid grounds of evidence.
Not only is Dr. Porter himself persuaded that there is no conclusive evidence for the Darwinian theory; but he asserts that "the practical common sense of mankind and the sagacious tact of most naturalists has [sic] usually decided. . . that under the present conditions or laws of being, within the historic period, the limits of well defined species have not been and are not likely to be changed." Evidently "the common sense of mankind and the sagacious tact of most naturalists" are very much on their guard. They don't want to decide anything rashly, so in delivering their opinion they stipulate for "present conditions" and "well-defined species" and "the historic period." Where they momentarily forget themselves is where they seem to stretch the historic period into the future, asserting that within the limits of that period "well-defined species are not likely to be changed." This is undoubtedly a slip on the part of the "common sense" and the "sagacious tact"; for a period can not be "historic" until it has had a history.
It is needless to say that Dr. Porter's opinion as to the unsatisfactory nature of the evidence for Darwinism is not conclusive. As he has appealed to the "sagacious tact of most naturalists," let us see what a naturalist and biologist of the highest order, the Rev. W. H. Dallinger, F. R. S., has to say on the question at issue in the very last number of the "Contemporary Review." These are the learned gentleman's words:
"The philosophical interpretation of modern biological knowledge which originated in Darwin, and has been universally received by trained and competent students, stands so securely that there is little need of additional facts to make it, so far as it is intended to reach, an immutable element, in all future time, in the interpretation of vital phenomena. Much may be added, but the philosophy of the 'Origin of Species' must remain. It is, however, a matter of the deepest interest and of much moment that the active investigations carried on by biologists all over the globe, not only give an unbroken stream of evidence coincident with the great law of variation and the survival of the fittest, but that, ever and again, facts of the largest import present themselves, that pour a flood of light, as unexpected as it is confirmatory, on this great biological law. It was a discovery of much philosophical value and biological interest, that the duck-bill and echidna were oviparous though mammals; this was a final confirma-
