darwin and modern science-第36章
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all be the ultimate basis of a genealogical tree。 We can； as Darwin rightly observed； only infer the line of descent from the degree of resemblance between single forms。 If we regard man as directly derived from primitive forms very far back； we have no way of explaining the many points of agreement between him and the monkeys in general； and the anthropoid apes in particular。 These must remain an inexplicable marvel。
I have thus； I trust； shown that the first class of special theories of descent； which assumes that man has developed； parallel with the monkeys； but without relation to them； from very low primitive forms cannot be upheld； because it fails to take into account the close structural affinity of man and monkeys。 I cannot but regard this hypothesis as lamentably retrograde； for it makes impossible any application of the facts that have been discovered in the course of the anatomical and embryological study of man and monkeys； and indeed prejudges investigations of that class as pointless。 The whole method is perverted； an unjustifiable theory of descent is first formulated with the aid of the imagination； and then we are asked to declare that all structural relations between man and monkeys； and between the different groups of the latter； are valueless；the fact being that they are the only true basis on which a genealogical tree can be constructed。
So much for this most modern method of classification； which has probably found adherents because it would deliver us from the relationship to apes which many people so much dislike。 In contrast to it we have the second class of special hypotheses of descent； which keeps strictly to the nearest structural relationships。 This is the only basis that justifies the drawing up of a special hypothesis of descent。 If this fundamental proposition be recognised； it will be admitted that the doctrine of special descent upheld by Haeckel； and set forth in Darwin's 〃Descent of Man〃； is still valid to…day。 In the genealogical tree； man's place is quite close to the anthropoid apes； these again have as their nearest relatives the lower Old World monkeys； and their progenitors must be sought among the less differentiated Platyrrhine monkeys； whose most important characters have been handed on to the present day New World monkeys。 How the different genera are to be arranged within the general scheme indicated depends in the main on the classificatory value attributed to individual characters。 This is particularly true in regard to Pithecanthropus； which I consider as the root of a branch which has sprung from the anthropoid ape root and has led up to man； the latter I have designated the family of the Hominidae。
For the rest； there are； as we have said； various possible ways of constructing the narrower genealogy within the limits of this branch including men and apes； and these methods will probably continue to change with the accumulation of new facts。 Haeckel himself has modified his genealogical tree of the Primates in certain details since the publication of his 〃Generelle Morphologie〃 in 1866； but its general basis remains the same。 （Haeckel's latest genealogical tree is to be found in his most recent work； 〃Unsere Ahnenreihe〃。 Jena； 1908。） All the special genealogical trees drawn up on the lines laid down by Haeckel and Darwin and that of Dubois may be specially mentionedare based； in general； on the close relationship of monkeys and men； although they may vary in detail。 Various hypotheses have been formulated on these lines； with special reference to the evolution of man。 〃Pithecanthropus〃 is regarded by some authorities as the direct ancestor of man； by others as a side… track failure in the attempt at the evolution of man。 The problem of the monophyletic or polyphyletic origin of the human race has also been much discussed。 Sergi （Sergi G。 〃Europa〃； 1908。） inclines towards the assumption of a polyphyletic origin of the three main races of man； the African primitive form of which has given rise also to the gorilla and chimpanzee； the Asiatic to the Orang； the Gibbon； and Pithecanthropus。 Kollmann regards existing human races as derived from small primitive races （pigmies）； and considers that Homo primigenius must have arisen in a secondary and degenerative manner。
But this is not the place； nor have I the space to criticise the various special theories of descent。 One； however； must receive particular notice。 According to Ameghino； the South American monkeys （Pitheculites） from the oldest Tertiary of the Pampas are the forms from which have arisen the existing American monkeys on the one hand； and on the other； the extinct South American Homunculidae； which are also small forms。 From these last； anthropoid apes and man have； he believes； been evolved。 Among the progenitors of man； Ameghino reckons the form discovered by him （Tetraprothomo）； from which a South American primitive man； Homo pampaeus； might be directly evolved； while on the other hand all the lower Old World monkeys may have arisen from older fossil South American forms （Clenialitidae）； the distribution of which may be explained by the bridge formerly existing between South America and Africa； as may be the derivation of all existing human races from Homo pampaeus。 （See Ameghino's latest paper； 〃Notas preliminares sobre el Tetraprothomo argentinus〃； etc。 〃Anales del Museo nacional de Buenos Aires〃； XVI。 pages 107…242； 1907。） The fossil forms discovered by Ameghino deserve the most minute investigation； as does also the fossil man from South America of which Lehmann…Nitsche （〃Nouvelles recherches sur la formation pampeenne et l'homme fossile de la Republique Argentine〃。 〃Rivista del Museo de la Plata〃； T。 XIV。 pages 193…488。） has made a thorough study。
It is obvious that； notwithstanding the necessity for fitting man's line of descent into the genealogical tree of the Primates； especially the apes； opinions in regard to it differ greatly in detail。 This could not be otherwise； since the different Primate forms； especially the fossil forms； are still far from being exhaustively known。 But one thing remains certain；the idea of the close relationship between man and monkeys set forth in Darwin's 〃Descent of Man〃。 Only those who deny the many points of agreement； the sole basis of classification； and thus of a natural genealogical tree； can look upon the position of Darwin and Haeckel as antiquated； or as standing on an insufficient foundation。 For such a genealogical tree is nothing more than a summarised representation of what is known in regard to the degree of resemblance between the different forms。
Darwin's work in regard to the descent of man has not been surpassed； the more we immerse ourselves in the study of the structural relationships between apes and man； the more is our path illumined by the clear light radiating from him； and through his calm and deliberate investigation； based on a mass of material in the accumulation of which he has never had an equal。 Darwin's fame will be bound up for all time with the unprejudiced investigation of the question of all questions； the descent of the human race。
VIII。 CHARLES DARWIN AS AN ANTHROPOLOGIST。
By ERNST HAECKEL。 Professor of Zoology in the University of Jena。
The great advance that anthropology has made in the second half of the nineteenth century is due in the first place； to Darwin's discovery of the origin of man。 No other problem in the whole field of research is so momentous as that of 〃Man's place in nature；〃 which was justly described by Huxley （1863） as the most fundamental of all questions。 Yet the scientific solution of this problem was impossible until the theory of descent had been established。
It is now a hundred years since the great French biologist Jean Lamarck published his 〃Philosophie Zoologique〃。 By a remarkable coincidence the year in which that work was issued； 1809； was the year of the birth of his most distinguished successor； Charles Darwin。 Lamarck had already recognised that the descent of man from a series of other Vertebratesthat is； from a series of Ape…like Primateswas essentially involved in the general theory of transformation which he had erected on a broad inductive basis； and he had sufficient penetration to detect the agencies that had been at work in the evolution of the erect bimanous man from the arboreal and quadrumanous ape。 He had； however； few empirical arguments to advance in support of his hypothesis； and it could not be established until the further development of the biological sciencesthe founding of comparative embryology by Baer （1828） and of the cell…theory by Schleiden and Schwann （1838）； the advance of physiology under Johannes Muller （1833）； and the enormous progress of palaeontology and comparative anatomy between 1820 and 1860provided this necessary foundation。 Darwin was the first to coordinate the ample results of these lines of research。 With no less comprehensiveness than discrimination he consolidated them as a basis of a modified theory of descent； and associated with them his own theory of natural selection； which we take to be distinctive of 〃Darwinism〃 in the stricter sense。 The illuminating truth of these cumulative arguments was so great in every branch of biology that； in spite of the most vehement opposition； the battle was won within a single decade； and Darwin secured the general admiration and recognition that had been denied to his forerunner； Lamarck； up to the hour of his death （1829）。
Before； however； we consider the momentous influence that Darwinism has had in anthropology； we shall find it useful to glance at its history in the course of the last half century； and notice the various theories that have contributed to its advance。 The first attempt to give extensive expression to the reform of biology by Darwin's work will be found in my 〃Generelle Morphologie〃 （1866） （〃Generelle Morphologie der Organismen〃； 2 vols。； Berlin； 1866。） which was followed by a more popular treatment of the subject in my 〃Naturliche Schopfungsgeschichte （1868） （English translation； 〃The History of Creation〃； London； 1876。）； a compilation from the earlier work。 In the first volume of the 〃Generelle Morphologie〃 I endeavoured to show the great importance of evolution in settling the fundamental questions of biological philosophy； especially in regard to comparative anatomy。 In the second volume I dealt broadly with the principle of evolution； distinguishing ontogeny and phylogeny as its two coordinate main branches； and associating the two in the Biogenetic Law。 The Law may be formulated thus： 〃Ontogeny （embryology or the development of the individual） is a concise and compressed recapitulation of phylogeny （the palaeontological or genealogical series） conditioned by laws of heredity and adaptation。〃 The 〃Systematic introduction to general evolution；〃 with which the second volume of the 〃Generelle Morphologie〃 opens； was the first attempt to draw up a natural system of organisms （in harmony with the principles of Lamarck and Darwin） in the form of a hypothetical pedigree； and was provisionally set forth in eight genealogical tables。
In the nineteenth chapter of the 〃Generelle Morphologie〃a part of which has been republished； without any alterati
