Many of the views here expressed are of a highly speculative nature,  and some of them will no doubt prove erroneous; but in every single case I have given reasons which led me to prefer one view to the other. It seemed, at any rate, worthwhile to test how far the principle of evolution was capable of throwing light on some of the most difficult problems in the natural history of man. False facts are extremely harmful to the progress of science, since they often take a long time to be recognized as true; but false views, if supported by some evidence, do little harm, because   everyone has the saving pleasure of proving them wrong in his turn; and when this is done, one of the paths to error is closed, and often at the same time the path to truth is opened.   The main conclusion reached here, and now accepted by many naturalists who are fully capable of sound judgment, is that man is descended from some less highly organized form. The foundations on which this assertion rests will never be shaken: the close resemblance between man and the lower animals in embryonic development, and in countless features of structure and constitution, both important and minute, together with the rudiments and abnormal reversions retained by him, to which he is sometimes subject - all these are facts that are not subject to dispute.  These facts have long been known, but until recently they did not tell us anything about the origin of man. Now that we consider them in the LIGHT of our knowledge of the whole organic world, it is impossible to mistake their meaning. The great principle of evolution is clearly and firmly established when these groups of facts are considered in connection with others, what is the mutual affinities between the members of the same group, their geographical distribution, past and present, and their geological sequence. It is impossible to believe that all these facts are false. Anyone who is not content, like the savage, with viewing the phenomena of nature as events unconnected with each other, will no longer be able to admit that man is the product of a separate act of creation.