268 



KNOWLEDGE 



[December 1, 1899. 



Esquimaux, possess a nasal aperture of intermediate form, 

 and are hence mesorhine; whilst the black races, including 

 Negroes, Australians, Tasmanians, etc., are platyrhine, 

 and have broad and open nasal apertures. 



Here, again, we have an instance of the correlation of 

 certain forms, the platyrhine type of nasal aperture is 

 usually associated with the prognathous or mesognathous 

 form of jaw ; the most noticeable exception to this rule 

 being the Bush race, which, although orthognathous, is 

 extremely platyrhine (index 59, Flower). 



The relation between the skeletal form of the orbits and 

 the external appearance of the eye, denoting thereby the 

 disposition of the eyelids, and the extent and direction of 

 the palpebral fissure, is not nearly so pronounced as the 

 association between the skeleton of the nose and its 

 external shape. If we except the pronounced projection 

 of the upper orbital margins which is so characteristic of 

 some races, and which imparts to the features an undue 

 projection to the eyebrows and a sunken appearance to 

 the eye, it is doubtful if modifications in the shape of the 

 orbital margins are at all recognisable on the living. 

 We find, however, that in the skull the form of the orbit 

 is subject to many variations. In order to estimate these 

 differences use is made of the orbital indox, which expresses 

 the proportionate height of the orbit as contrasted with 

 its width. Orbitalhejgh t x 100 ^ ^ q^^-^^^^ ^^^^^^ 

 Orbital width 

 When the index falls below 84 the skull is described 

 as Microseme — that is to say, it possesses an orbit of 

 more or less oblong form, the height beins: much less 

 than the width. When the index is above 89 the aperture 

 is more circular in shape, and the skull displaying this 

 form is called Megascme. 



The intermediate form with indices varying from 84 

 to 89 belong to the Mtsoseme group. 



Just as we have seen a correlation between the dental, 

 the gnathic and the nasal indices, so we recognise a like 

 tendency in regard to the orbital index, though not so 

 marked. 



This is borne out by an examination of the table 

 prepared by the late Sir W. Flower, and published in the 

 Osteological Catalogue (Man) of the Museum of the 

 College of Surgeons. In no race in which the orbits are 

 megaseme is the skull either prognathous or platyrhine ; 

 on the other hand, if we except Guanches and Bushmen, 

 we find microseme skulls displaying both platyrhine and 

 prognathous conditions. 



There is some justification therefore for the assumption 

 that, given a human tooth, preferably a molar, we might 

 from a consideration of its size form some general idea of 

 the architecture of the face of the individual to whom it 

 once belonged. 



Unfortunately the space at our disposal prevents us for 

 the present from referring to many other points in con- 

 nection with the disposition and arrangement of the bones 

 of the facial skeleton. 



SECRETS OF THE EARTH'S CRUST. 



By Grenyille A. J. Cole, m.r.i.a., f.g.s., Professor of 

 Geology in the Royal College of Science for Ireland. 



VI.— THE COMING OP MAN. 



AN presents himself to the calm and enquiring 

 eye of science in so many aspects, in so many 

 fields of enterprise, that it is difficult to deal 

 comprehensively with his career upon the earth, 

 as we might with that of the cockle or the cray- 

 He is so near us, even in the i\Ialay or the Negro, 



M 



fish. 



that we are apt to place him in a category apart from the 

 rest of animated nature. Even the young science of 

 anthropology, by t very title, confesses that zoology can- 

 not cope unaided with the details daily provided by the 

 aberrant activity of mankind. 



The geologist can make no claim to discuss the specific 

 isolation of man, or the origin of his infinite resource. 

 The "god-Uke apprehension" that gives us on the one 

 hand the dynamite gun, and on the other the Society for 

 the Prevention of Cruelty to Animals, may well stagger a 

 philosopher. Most enquirers are content to retire from 

 this field, observing " there is something in this more than 

 natural, if philosophy could find it out." But the first 

 appearance of man upon the earth, which was formerly 

 regarded as a matter for historians, has become more and 

 more a question of pure geology. Whether the archaeo- 

 logist desires it or no, he has already been forced to take 

 coimsel with the stratigrapher in his researches into the 

 earth's crust. 



When Sir- C. Lyell, in 18C3, issued his " Geological 

 Evidences of the Antiquity of Man," a book that ran into 

 three editions in ten months, he took the position that the 

 principles of geology and palaeontology must be applied to 

 the solution of the question. He thus observed* that the 

 shell-mounds accumulated by ancient dwellers on the 

 Baltic contain shells of marine species of full growth, 

 whereas those at present living in the adjacent sea have 

 been dwarfed by brackish-water conditions. Or, again, he 

 pointed out (p. 227) the identity of some of the mammalia 

 of the Norfolk Forest-bed with those stOl contemporary 

 with man, as indicating that we need not " despair of one 

 day meeting with the signs of man's existence in the 

 forest-bed." At that time, the occurrence of man in 

 preglacial epochs was held to be in the highest degree 

 improbable, and archfeologists may be found at the present 

 day who look upon LyeU's suggestion as still wild in the 

 extreme. 



The remains of man are notably subject to decay, and 

 the signs of his former existence in this or that locality 

 often depend upon the more enduring objects that his skill 

 has left behind. Baked pottery, chipped stone implements, 

 the very charcoal of his fires, may survive in places where 

 his own bones are extremely rare. Much of our knowledge 

 of early man is derived from interments conducted with 

 careful ritual by his tribal fellows. Is it likely that, in a 

 ruder age, when ceremonial burial may have been utterly 

 unknown, the skeleton of man would have much chance of 

 preservation ? 



Even more robust terrestrial animals may be little 

 known in a fossil state, except in certain fortunate locali- 

 ties. Our acquaintance with the Lower Pliocene or Upper 

 Miocene vertebrate fauna of Europe, to take one example, 

 would be limited, were it not for the local accumulations 

 of skeletons at the farm of Pikermi in Attica, and Mont 

 Luberon in Provence. In neither of these cases is the 

 deposit truly terrestrial ; water has brought together the 

 remains, and alluvial mud or gravel has entombed 

 them. At Pikermi, the torrent which swept down the 

 large bones has removed those of the numerous small 

 animals, which must have existed equally on the soil of 

 antique Greece. Hence, even here, the record of the fauna 

 is imperfect. 



Unlike many other mammals, early man was not com- 

 pelled to collect in vast herds around the lakes and water- 

 courses. His very intelligence, his variety of aim, made 

 him a wanderer across the earth. Dying in the forest, or 

 on the barren rock, or isolated in his log-canoe, his skeleton 



* "Antiquity of Man," 3rd ed., p. 13. 



