Page:Popular Science Monthly Volume 72.djvu/56

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HE localization through war and barter of the cerebral centers of speech and writing (and hence of intellect) of 98 per cent, of the population in the left half-brain is the cause of right-handedness. The increase of the necessary differentiation of bodily and mental function by the coordination of associated cerebral centers has resulted in a general right-handedness, right-eyedness, etc., the data by vision, audition, and for action of the right leg and foot for associated function, compelling a location of all these centers in the same left-brain and closely linked with the determining faculty of speech and writing. With the two per cent, of left-handed, the reverse of all this takes place. The mystery of the origin of right-handedness is thus cleared up. With this explanation manifest the other concurrent mystery of the rule of the road is of easy solution. Eight-handedness, plus the variant circumstances of civilization, the reaction of the right-handed organism to the environment (in the language of evolution), explains all the puzzles of the rule of the road.

Primitive war, as Homer, chivalry, and present-day savage customs demonstrate, regardless of the number of combatants, was a matter of individual encounter, of hand-to-hand conflict. Even when archery, and throwing of spears, javelins, etc., came into use the essential individualism was not changed, and the shielding of the left side, and aggressive use of the right hand continued. All military tactics and drill of numbers was then established as right-handed, down to the most minute particular—and so continues, indeed, although the flung weapon weighs a thousand pounds instead of one or two pounds, and is thrown five miles instead of twenty or fifty feet. After the Trojan war, chariots fell more and more into disuse, and cavalry began to take their place, but this in no way changed the evolution of right-handed tactics. In Alexander's time the right flank of the phalanx was the post of honor, called the head, the left the tail, and marches and movements were made by the right. The commander had his station on the right. So strongly established was right-handedness as early as the half-legendary Amazonian times, that the Amazon had her right breast excised in order that she might hurl the javelin and shoot the arrow with greater freedom and accuracy.