434 



NA TURE 



[March 9, 1905 



905 f; 



Leaving out of account the oracular statement quoted 

 from Klaatsch, there can be no question that Mr. 

 Duckworth's inference as to man's line of ancestors 

 is much less definite than that of Darwin, and 

 certainly, in the opinion of many well qualified to 

 judge, less in keeping with the evidence at our dis- 

 posal. What the peculiar primitive characters of the 

 liuman hand and foot may be the writer cannot guess, 

 but it is certain that there are numerous characters in 

 the human hand and foot which can be accounted 

 for only on the supposition that at one time they 

 were used functionally as are now the hands and 

 feet of anthropoids. Mr. Duckworth states his 

 opinion guardedly, but it is evident from the state- 

 ment just quoted that he believes the line of ancestors 

 that connect modern man with a primitive lemuroid 

 (Eocene) stock is e.xtinct and unknown, and that this 

 line of ancestry runs an independent and parallel 

 course to the ancestral stock of the anthropoids. 

 Now man shares with the chimpanzee and gorilla 

 some three hundred structural features which are not 

 possessed by any lemuroid form of which we have 

 any knowledge, nor can the common possession of 

 these characters be accounted for except on the sup- 

 position that man and these two anthropoids are 

 derived from a common stock. A full investigation 

 of the evidence will show that Darwin was not far 

 from the truth when he supposed that the gorilla, 

 the chimpanzee, and man have their origin from a 

 common stock. Modern man differs from the 

 -Miocene anthropoid Dryopithecus in structure no 

 more than does the modern horse from its 

 Miocene ancestor. In Dryopithecus, characters 

 are recognisable which link it with the gibbon 

 on the one hand and the chimpanzee on the 

 other. Palieopithecus, a Pliocene anthropoid, in the 

 characters of its teeth and jaw, which are the only 

 parts yet found, links the chimpanzee to the orang. 

 The modern gibbon differs in an incredibly small 

 degree from its Miocene ancestor, and shares many 

 characters in common with the great anthropoids, 

 man, the Old World monkeys, and New \\'orld 

 monkevs, and is by far the most generalised form of 

 higher Primate now extant, in spite of many adaptive 

 features. In short, the evidence jxjints to the common 

 origin of man and the great anthropoids from a 

 gibbon (Hylobatian) stock ; this in turn, with 

 monkevs, must be traced to a lemuroid origin. 



.Mr. Duckworth deals verj- justly with the evidence 

 vielded bv embryological investigation. Thirty years 

 ago, when it was believed that the embryo recapitu- 

 lated its ancestral stages in iitero, it was thought 

 that the history of man could be written when his 

 development became known. " Palaeontology is 

 good but Embryology is better," wrote Kitchen 

 Parker, but now we know, and Mr. Duckworth 

 states the case fully, that the embryological phases 

 are so obscure that they can only be construed by 

 the help of comparative anatomy and palaeontology. 

 It has come to be recognised that every mammal is 

 adapted to two separate lives — an intra-uterine life 

 and an independent life ; the features of the one 

 NO. 1845, VOL. 71] 



existence mask those of the other. Yet Mr. Duck- 

 worth makes the important fact stand out that the 

 intra-uterine life of man is exactly similar, so far as 

 we yet know, to that of the anthropoids, and in that, 

 while it resembles in most points the lower Primates, 

 yet differs from all other mammals. 



It must be admitted that Mr. Duckworth's task 

 was not an easy one ; yet no essential or important 

 contribution has been passed unnoticed by him. His 

 statements are clear and impartial ; he has even a 

 kindlv word to say for some notions, such as the 

 temporary fissures of the brain, which most 

 anatomists, in common with himself, now regard 

 as post-mortem artefacts. In another edition, which 

 this work is certain to attain, the statements made 

 in the following sentence (p. 201) will require some 

 amendment : — 



" Selenka thus regards the syncytium (a peculiar 

 tissue) as derived neither from the chorion-entoderm 

 (Kollmann), nor from the submucous uterine decidual 

 connective tissue cells (Minot, ' Human Embry- 

 ology,' pp. 13 and 375) nor from the foetal ecto- 

 derm (Robinson, ' Hunterian Lectures,' Journal of 

 Anatomy and Physiology, vol. xxxviii. p. 493), but 

 from the epithelial lining of the uterus." 



Mr. Duckworth unwittingly does the late Prof. 

 Selenka a double injustice ; in the first place he 

 reproduces an acknowledged modification (Fig. 148, 

 p. 203) of a figure by Selenka, in which the syncytium 

 is made to appear as a continuation of the lining 

 epithelium of the uterus, whereas in Selenka 's figure 

 it is clearly shown not to be continuous; secondly, 

 Selenka (" Studien ueber Entwickelungsgeschichte," 

 Heft viii., pp. 190, 193) expressly states that he is 

 uncertain of the origin of the syncytium, but that the 

 evidence is rather in favour of its origin from the 

 cells of the uterine glands. Expert opinion regards 

 it as settled that the syncytium does not so arise, 

 but springs from the ectoderm of the embryo, a 

 conclusion which seemed to Selenka not improbable. 

 He does Kollmann also an injustice, for in his text- 

 book (p. 201) that author expressly states that it arises 

 from the lining epithelium of the uterus — the opinion 

 ascribed by Mr. Duckworth to Selenka. Nor will 

 Minot acknowledge the opinion ascribed to him, for 

 on p. 322 of a text-book on human embryology 

 he states that he is convinced that the syncytium is 

 derived from the embryonic (chorionic) ectoderm, the 

 opinion here ascribed to Prof. Robinson. Nor will 

 Prof. Robinson be willing to accept priority for the 

 theory of the ectodermal origin of the syncytium ; 

 probably Hubrecht has the greatest claim to be 

 accounted the pioneer in this matter. 



It would not be just to close this review without 

 acknowledging the number of original facts and 

 fresh opinions that mark the pages of this work. 

 The opening chapters are perhaps too condensed ; the 

 long lists of characters enumerated arc rather apt to 

 lend to mental dyspepsia even in the pages of a 

 text-book, and one misses a statement of their func- 

 tional meaning, which would greatly assist the 

 memory in ranking them together. The chapters on 



