5 8 2 TEE POPULAR SCIENCE MONTHLY. 



the weakening of the latter might mean the (relative) strengthening 

 of the former. But such is not the case : the theologian, as a theo- 

 logian, can only say, " God made the world " ; science alone can under- 

 take 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 conclu- 

 sive 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 con- 

 ditions 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 with- 

 in 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 unsatis- 

 factory 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 gen- 

 tleman'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 in- 

 terest 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 pre- 

 sent themselves, that pour a flood of light, as unexpected as it is con- 

 firmatory, 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- 



