Identifier: mansplaceinnatur01huxl (find matches)
Title: Man's place in nature, and other anthropological essays
Year: 1904 (1900s)
Authors: Huxley, Thomas Henry, 1825-1895
Subjects: Human beings Apes Ethnology Indo-Europeans
Publisher: New York, J. A. Hill and company
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

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tionswhich the skull undergoes in ascending from the lower animalsup to man. In such a mammal as a Beaver (Fig. 29), a line (ah) drawnthrough the bones, termed basioccipital, basisphenoid, and pres-phenoid, is very long in proportion to the extreme length of thecavity which contains the cerebral hemispheres (g h). The planeof the occipital foramen (he) forms a slightly acute angle withthis basicranial axis, while the plane of the tentorium (i T)is inclined at rather more than 90° to the basicranial axis;and so is the plane of the perforated plate (ad), by which thefilaments of the olfactory nerve leave the skull. Again, a line 114 MANS PLACE IN NATURE. drawn tlirough tlie axis of the face, between the hones called eth-moid and vomer — the basifacial axis (f. e.) forms an exceed-ingly obtuse angle, where, when produced, it cuts the basicranial axis. If the angle made by the line h c with a h, be called the occipitalangle, and the angle made by the line a d with a & be termed the
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Fig. 30.—Sections of orthognathous (light contour) and prognathous(dark contour) skulls, one-third of the natural size, a h, Basicranialaxis; he, h c, plane of the occipital foramen; d d, hinder end of thepalatine bone; e e front end of the upper jaw; T T, insertion of thetentorium. olfactory angle and that made by * T with a h the tentorialangle then all these, in the mammal in question, are nearlyright angles, varying between 80° and 110°. The angle e f h,or that made by the cranial with the facial axis, and which may FOSSIL REMAINS OF MAN. 115 be termed the craniofacial angle, is extremely obtuse, amount-ing, in the case of the Beaver, to at least 150°. But if a series of sections of mammalian skulls, intermediatebetween a Bodent and a Man (Fig. 29), be examined, it will befound that in the higher crania the basicranial axis becomesshorter relatively to the cerebral length; that the olfactory an-gle and occipital angle become more obtuse; and that the craniofacial angle, becom

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