Septemuek 14, 1888.] 



SCIENCE. 



carefully by reflected light, it is seen that the ground-tone of the 

 Mongolian is bluish, while that of the American is reddish. 



Of positive cranial characteristics of the red race, I call attention 

 to the interparietal bone (or os Incai), which is found in its extreme 

 development in the American, in its greatest rarity among the Mon- 

 golians ; also to the form of the glabella, found most prominent in 

 American crania, least prominent in Altaic or northern Mongoloid 

 crania ; and the peculiar American characteristics of the occipital 

 bone, ilattened externally, and internally presenting in nearly forty 

 per cent of cases the 'Aymarian depression,' as it has been termed, 

 instead of the internal occipital protuberance (H®velaC(JUE et 

 HERVjf, Anihropologic, pp. 231, 234, 236). 



The shape of the skull has been made another ground of race- 

 distinction; and, although we have learned of late years that its 

 value was greatly over-estimated by the earlier craniologists, we 

 have also learned that in the average, and throughout large num- 

 bers of peoples, it is a most persistent characteristic, and one 

 potently indicative of descent or relationship. Now, of all the 

 peoples of the world, the Mongols, especially the Turanian branch, 

 are the most brachycephalic ; they have the roundest heads ; and 

 it is in a high degree noteworthy that precisely the American 

 nation dwelling nearest to these, having undoubted contact with 

 them for unnumbered generations, are long-headed, or dolicho- 

 cephalic, in a marked degree. I mean the Eskimo, and I cannot 

 but be surprised that such an eminent anthropologist as Virchow 

 (in VerhandluHgeit der Berliner Anthrop. Gesellscluift, 1881-82), 

 in spite of this anatomical fact, and in defiance of the linguistic evi- 

 dence, should have repeated the assertion that the Eskimo are of 

 Mongolian descent. 



Throughout the American contment generally, the natives were 

 not markedly brachycephalic. This was abundantly illustrated 

 more than twenty years ago by the late Prof. James Aitkins Meigs, 

 in his ' Observations on the Cranial Forms of the American Abo- 

 rigines.' They certainly, in this respect, show no greater Mongoloid 

 affinities than do their white successors on the soil of the United 

 States. 



If color, hair, and crania are thus shown to present such feeble 

 similarities, what is it that has given rise to a notion of the Mongoloid 

 origin of the American Indian .' Is it the so-called Mongolian eye, 

 the oblique eye, with a seeming droop at its inner canthus .' Yes, 

 a good deal has been made of this by certain writers, especially by 

 travellers who are not anatomists. The distinguished ethnologist 

 Topinard says the Chinese are very often found without it, and I 

 can confirm this opinion by those I have seen in this country. It is, 

 indeed, a slight deformity, affecting the skin of the eyebrow only, 

 and is not at all infrequent in the white race. Surgeons know it 

 under the name epicanthus. and, as with us it is considered a dis- 

 figurement, it is usually removed in infancy by a slight operation. 

 In a few American tribes it is rather prevalent, but in most of the 

 pure Indians I have seen, no trace of it was visible. It certainly 

 does not rank as a racial characteristic. 



The nasal index has been recommended by some anatomist as 

 one of the most persistent and trustworthy of racial indications. 

 The. Mongolian origin of the red race derives faint support from 

 this quarter. From the measurements given in the last edition of 

 Topinard's work (Eleincnfs d'Aniliropohgie, p. 1003), the Mongo- 

 lian index is So. while that of the Eskimo and tribes of the United 

 States and Canada, as far as observed, is 70, that of the average 

 Parisian of to-day being 69 (omitting fractions). According to this 

 test, the American is much closer to the white than to the yellow 

 race. 



Most of the writers (for instance, Ave-Lallemant, St. Hilaire, 

 Peschel, and \'irchow) who have argued for the Mongoloid charac- 

 ter of the Americans have quoted some one tribe who, it is asserted, 

 shows marked Chinese traits. This has especially been said of the 

 natives of three localities, — the Eskimo, the tribes of the North 

 Pacific coast, and the Botocudo of Brazil. So far as the last-men- 

 tioned are concerned, the Botocudo, any such similarity has been 

 categorically denied by the latest and most scientific traveller who 

 has visited them, Dr. Paul Ehrenreich. It is enough if I refer you 

 to his paper in the Zcitsclirift fiir Etlinoloi^ic for 1SS7, where he 

 dismisses, I should say once for all, the notion of any such resem- 

 blance existing. I have already pointed out that the Eskimo are 



totally un-Mongolian in cranial shape, in nasal index, and in lin- 

 guistic character. They do possess in some instances a general 

 physiognomical similarity, and this is all ; and this is not worth 

 much as against the dissimilarities mentioned. The same is true 

 of the differences and similarities of some tribes of the north-west 

 coast. In estimating the value of any resemblances observed in 

 this part of our continent, we should remember that we have suffi- 

 cient evidence to believe that for many generations some slight 

 intercourse has been going on between the adjacent mainlands and 

 islands of the two continents in the regions of their nearest prox- 

 imity. The same train of events led to a blending of the negro 

 and the white races along the shores of the Red Sea ; but any one 

 who recognizes the distinction of races at all — and I am aware 

 that certain eccentric anthropologists do not — will not, on that 

 account, claim that the white race is negroid. With just as little 

 reason, it seems to me, has it been argued that the native Ameri- 

 cans as a race are Mongoloid. 



ON THE CAUSES OF VARIATION IN ORGANIC 

 FORMS.' 



The fundamental principle of organic evolution is natural selec- 

 tion, which is based on individual variation and the struggle for 

 existence, the effect of which is the preservation of the most com- 

 petent. It is extremely difficult to get at the immediate cause or 

 causes of this individual variation, and for this reason Darwin con- 

 sidered it promiscuous and aimless, though he wisely avoided call- 

 ing it lawless. There is no more fascinating or profitable field of 

 investigation than that leading to the proximate cause or causes of 

 variation. We are not content to rest the case where Darwin did 

 by recognizing variation as an inherent principle in organic forms, 

 or to beg the question by saying that it is as much a necessity of 

 life as natural selection itself. Let us, therefore, discuss these 

 causes in the light of recent experience and experiment. 



We soon find that they admit of a certain amount of classifica- 

 tion, the minor divisions of which, as in all systems of classification, 

 more or less fully interlock or blend. They fall, however, into two 

 chief categories : viz., (i) external conditions or environment, which 

 are, at bottom, physical ; and (2) internal tendencies or promptings, 

 which are, at bottom, psychical. 



By external conditions or environment, we include all influences 

 on organisms which act from without ; and in carefully considering 

 them we shall find it difficult to draw the line between those which 

 are really external and independent of any motive or inherent ten- 

 dency in the organism, and those which are not. Hence the gen- 

 eral term 'external conditions' is resolvable into various minor 

 factors. 



No one can well study organic life, especially in its lower mani- 

 festations, without being impressed with the great power of the 

 environment. Joseph LeConte speaks of the organic kingdom lying, 

 as it were, " passive and plastic in the moulding hands of the en- 

 vironment." In Semper's ' Animal Life' we have the best syste- 

 matized effort to bring together the direct causes of variation : and 

 no one who has read through its pages can doubt the direct modi- 

 fying influences of nutrition, light, temperature, water at rest and 

 in motion, atmosphere still or in motion, etc., or question his con- 

 clusion that no power which is able to act only as a selective and 

 not as a transforming influence can ever be exclusively put forth as 

 a causa efficicns of the phenomena. 



It is among the vital or organic conditions of variation that nat- 

 ural selection has fullest sway ; and, as they have been so ably 

 expounded by Darwin and others, I will at once pass to a consid- 

 eration of the second class of causes, to which the study of the 

 interaction of organisms leads, — the internal conditions. 



First of these we will consider the physiological causes. Genesis 

 itself is the first and most fundamental of all causes of variation. 

 The philosophy of sex may, indeed, be sought in this differentia- 

 tion, as the accumulated qualities in separate entities, when suddenly 

 conjoined or commingled, inevitably lead to aggregation and hetero- 

 geneity ; in other words, to plasticity or capacity to vary. Genesis, 



' Abstr.ict of an address twforc the Section of Biology of the American Association 

 for the Advancement of Science, at Cleveland, O., Aug. is-m, iS83, by C. V. Riley, 

 vice-president of the section. 



