n earlier years； and especially during his splendid period of activity at Wurzburg （1848…1856）； he had been a consistent free…thinker； and had in a number of able articles （collected in his 〃Gesammelte Abhandlungen〃） （〃Gesammelte Abhandlungen zur wissenschaftlichen Medizin〃； Berlin； 1856。） upheld the unity of human nature； the inseparability of body and spirit。 In later years at Berlin； where he was more occupied with political work and sociology （especially after 1866）； he abandoned the positive monistic position for one of agnosticism and scepticism； and made concessions to the dualistic dogma of a spiritual world apart from the material frame。
In the course of a Scientific Congress at Munich in 1877 the conflict of these antithetic views of nature came into sharp relief。 At this memorable Congress I had undertaken to deliver the first address （September 18th） on the subject of 〃Modern evolution in relation to the whole of science。〃 I maintained that Darwin's theory not only solved the great problem of the origin of species； but that its implications； especially in regard to the nature of man； threw considerable light on the whole of science； and on anthropology in particular。 The discovery of the real origin of man by evolution from a long series of mammal ancestors threw light on his place in nature in every aspect； as Huxley had already shown in his excellent lectures of 1863。 Just as all the organs and tissues of the human body had originated from those of the nearest related mammals； certain ape…like forms； so we were bound to conclude that his mental qualities also had been derived from those of his extinct primate ancestor。
This monistic view of the origin and nature of man； which is now admitted by nearly all who have the requisite acquaintance with biology； and approach the subject without prejudice； encountered a sharp opposition at that time。 The opposition found its strongest expression in an address that Virchow delivered at Munich four days afterwards （September 22nd）； on 〃The freedom of science in the modern State。〃 He spoke of the theory of evolution as an unproved hypothesis； and declared that it ought not to be taught in the schools； because it was dangerous to the State。 〃We must not；〃 he said； 〃teach that man has descended from the ape or any other animal。〃 When Darwin； usually so lenient in his judgment； read the English translation of Virchow's speech； he expressed his disapproval in strong terms。 But the great authority that Virchow hadan authority well founded in pathology and sociologyand his prestige as President of the German Anthropological Society； had the effect of preventing any member of the Society from raising serious opposition to him for thirty years。 Numbers of journals and treatises repeated his dogmatic statement： 〃It is quite certain that man has descended neither from the ape nor from any other animal。〃 In this he persisted till his death in 1902。 Since that time the whole position of German anthropology has changed。 The question is no longer whether man was created by a distinct supernatural act or evolved from other mammals； but to which line of the animal hierarchy we must look for the actual series of ancestors。 The interested reader will find an account of this 〃battle of Munich〃 （1877） in my three Berlin lectures （April； 1905） （〃Der Kampf um die Entwickelungs…Gedanken〃。 （English translation； 〃Last Words on Evolution〃； London； 1906。）
The main points in our genealogical tree were clearly recognised by Darwin in the sixth chapter of the 〃Descent of Man〃。 Lowly organised fishes； like the lancelet （Amphioxus）； are descended from lower invertebrates resembling the larvae of an existing Tunicate （Appendicularia）。 From these primitive fishes were evolved higher fishes of the ganoid type and others of the type of Lepidosiren （Dipneusta）。 It is a very small step from these to the Amphibia：
〃In the class of mammals the steps are not difficult to conceive which led from the ancient Monotremata to the ancient Marsupials； and from these to the early progenitors of the placental mammals。 We may thus ascend to the Lemuridae； and the interval is not very wide from these to the Simiadae。 The Simiadae then branched off into two great stems； the New World and Old World monkeys； and from the latter； at a remote period； Man； the wonder and glory of the Universe； proceeded。〃 （〃Descent of Man〃 （Popular Edition）； page 255。）
In these few lines Darwin clearly indicated the way in which we were to conceive our ancestral series within the vertebrates。 It is fully confirmed by all the arguments of comparative anatomy and embryology； of palaeontology and physiology； and all the research of the subsequent forty years has gone to establish it。 The deep interest in geology which Darwin maintained throughout his life and his complete knowledge of palaeontology enabled him to grasp the fundamental importance of the palaeontological record more clearly than anthropologists and zoologists usually do。
There has been much debate in subsequent decades whether Darwin himself maintained that man was descended from the ape； and many writers have sought to deny it。 But the lines I have quoted verbatim from the conclusion of the sixth chapter of the 〃Descent of Man〃 （1871） leave no doubt that he was as firmly convinced of it as was his great precursor Jean Lamarck in 1809。 Moreover； Darwin adds； with particular explicitness； in the 〃general summary and conclusion〃 （chapter XXI。） of that standard work （〃Descent of Man〃； page 930。）：
〃By considering the embryological structure of manthe homologies which he presents with the lower animals；the rudiments which he retains；and the reversions to which he is liable； we can partly recall in imagination the former condition of our early progenitors； and can approximately place them in their proper place in the zoological series。 We thus learn that man is descended from a hairy； tailed quadruped； probably arboreal in its habits； and an inhabitant of the Old World。 This creature； if its whole structure had been examined by a naturalist； would have been classed amongst the Quadrumana； as surely as the still more ancient progenitor of the Old and New World monkeys。〃
These clear and definite lines leave no doubt that Darwinso critical and cautious in regard to important conclusionswas quite as firmly convinced of the descent of man from the apes （the Catarrhinae； in particular） as Lamarck was in 1809 and Huxley in 1863。
It is to be noted particularly that； in these and other observations on the subject； Darwin decidedly assumes the monophyletic origin of the mammals； including man。 It is my own conviction that this is of the greatest importance。 A number of difficult questions in regard to the development of man； in respect of anatomy； physiology； psychology； and embryology； are easily settled if we do not merely extend our progonotaxis to our nearest relatives； the anthropoid apes and the tailed monkeys from which these have descended； but go further back and find an ancestor in the group of the Lemuridae； and still further back to the Marsupials and Monotremata。 The essential identity of all the Mammals in point of anatomical structure and embryonic developmentin spite of their astonishing differences in external appearance and habits of lifeis so palpably significant that modern zoologists are agreed in the hypothesis that they have all sprung from a common root； and that this root may be sought in the earlier Palaeozoic Amphibia。
The fundamental importance of this comparative morphology of the Mammals； as a sound basis of scientific anthropology； was recognised just before the beginning of the nineteenth century； when Lamarck first emphasised （1794） the division of the animal kingdom into Vertebrates and Invertebrates。 Even thirteen years earlier （1781）； when Goethe made a close study of the mammal skeleton in the Anatomical Institute at Jena； he was intensely interested to find that the composition of the skull was the same in man as in the other mammals。 His discovery of the os intermaxillare in man （1784）； which was contradicted by most of the anatomists of the time； and his ingenious 〃vertebral theory of the skull；〃 were the splendid fruit of his morphological studies。 They remind us how Germany's greatest philosopher and poet was for many years ardently absorbed in the comparative anatomy of man and the mammals； and how he divined that their wonderful identity in structure was no mere superficial resemblance； but pointed to a deep internal connection。 In my 〃Generelle Morphologie〃 （1866）； in which I published the first attempts to construct phylogenetic trees； I have given a number of remarkable theses of Goethe； which may be called 〃phyletic prophecies。〃 They justify us in regarding him as a precursor of Darwin。
In the ensuing forty years I have made many conscientious efforts to penetrate further along that line of anthropological research that was opened up by Goethe； Lamarck； and Darwin。 I have brought together the many valuable results that have constantly been reached in comparative anatomy； physiology； ontogeny； and palaeontology； and maintained the effort to reform the classification of animals and plants in an evol