Ethnology : in two parts, I. Fundamental ethnical problems. II. The primary ethnical groups / by A.H. Keane.

  • Augustus Henry Keane
Date:
1896
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Licence: Public Domain Mark

Credit: Ethnology : in two parts, I. Fundamental ethnical problems. II. The primary ethnical groups / by A.H. Keane. Source: Wellcome Collection.

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    Determi- nantsofmental power less the volume of the brain than its convolutions and cellular structure. Yet the mental advance is unquestioned, and this advance- ment would be found to correspond with the physical advancement, were the brain, and not merely the skull, of the early Egyptians and of neolithic man available for comparative purposes. But the con- trast would have to be sought not so much in the respective volumes (size and weight), as in the sinuosities or convolutions of the inner white substance, and especially in the cellular structure of the thin outer cortex or envelope of grey matter which follows all the inner convolutions, with which it is also connected by an exceedingly complex nervous system. The countless cells of the cortical matter, fed through the nerves by the white sub- stance, are the ultimate seat of mental energy, and here is found the field in which this deHcate organ and its function, thought, may acquire indefinite expansion. The development of the cellular tissue, with a corresponding increase of mental power, apparently goes on until arrested by the closure of the cranial sutures. All the serratures are stated to be more complex in the higher than in the lower races, and their definite closing appears to be delayed till a later period in life amongst the former than amongst the latter. This physiological character, to which Filippo Manetta was the first to call attention in connection with racial differences \ has recently been noticed by two intelligent observers, Col. Ellis amongst the Upper Guinea peoples, and Captain Binger amongst the West Sudanese populations generally. The Black is a child, says this writer, and will long remain so; and the sudden arrest of the intellectual faculties at the age of puberty is attributed to the premature closing of the sutures^. Broca also has noticed that in idiots the soldering takes place early in These ele- ments capable of indefinite expansion till arrested by the closing of the cranial su- tures. Different degrees of in- telligence in different races accounted for. 1 La Razza Negra nel suo staid selvaggio &c., Turin, 1864, p. 20. - The Ewe-speaki?ig peoples, 1890, pp. 9-10. 3 A cet arret intellecluel doit correspondre, dans ces regions [Sudan], la soudure de la boite cervicale: le developpement du cr3.ne s'arrete et empeche le cerveau de se dilater davantage (Du Niger an Golfe de Guink, 1892, II. p. 246).
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