Darwin made easy / by Edward B. Aveling.

  • Edward Aveling
Date:
1893
Catalogue details

Licence: Public Domain Mark

Credit: Darwin made easy / by Edward B. Aveling. Source: Wellcome Collection.

    147/156 page 43
    The case of Backe has already been noted as exceptional. Eat placing him on one side, we have the startling fact that normal human parents have given birth to offspring whose brain capacities are far below those of man’s nearest allies. The difference between the 296 of Marguerite Maehler and the 1,900 of some modern Parisians is over 1,600 c. c. And yet both these are members of the human race. (b) Shape.—The human brain is, to use a common-place phrase, almost as broad as it is long, becoming in some cases nearly of a circular outline. On the other hand, the brains of the lower Primates are relatively longer than broad. Those of the Anthropomorpha, as usual, present characters more nearly allied to the human than to those of the C£$arrhine brain, for example, and, indeed, in some cases actually overlap, as it were, the human brain. The Chim- panzee has a brain ovoid (or egg-like) in shape but rather short and broad. The Gorilla’s brain is less ovoid than that of the Chimpanzee, and is relatively broader than that of any other anthropoid. The Orang, whilst differing in certain particulars from Man more than its and his allies, approaches him in others. The beak-like frontal lobes make the outline of the Orang brain much less human in aspect than are the outlines of those of the other two apes. The overlapping mentioned ..above is illustrated by the account given by Marshall [“ Philosophical Transactions,” 1884] of the brain of a Bushwoman dissected by him. Its shape was “ long, narrow, ovoid.” But in one very important point the Orang ranks highest. That is in the want of symmetry of the two halves of its brain. The convolutions of the right and left hemispheres respectively do not correspond exactly. This is also the case in a yet more marked degree in the brain of Man. Here the symmetry is more noticeable than in any of the Anthropo- morpha, in all of whom it is to be seen ; even more noticeable than in the Orang, whose brain exhibits this characteristic most clearly as far as the anthropoids are concerned. Is there any reason foy this want of correspondence in the arrangement of the brain-folds in the higher Primates ? The suggestion of Bastian [“ Brain as an Organ of Mind,” p. 41 Oj is that it is connected with a functional inequality between the two hemispheres. The suggestion is a luminous one
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