WHY ARE WE RIGHT-HANDED

Manawatu Times, Volume II, Issue 94, 12 September 1877, Page 3

WHY ARE WE RIGHT-HANDED

Investigations which were . very recently carried through ( by a French physician, Dr. Fleury, Bordeaux, nave adduced facts showing that our natural impulseto use" the members on the right side of the body is clearly traceable to probably physiological causes. Dr. Fleury, after examining an. immense number of human brains, asserts ilhat the left anterior lobe is a' little larger than the right one. Again, he , shows, that, by examining a large number of people, there is an unequal, supply of blood to the two sides of the "body. The braehiocephalie trunk, which only exists on the right of the arch of the aorta, produces, by a difference m termination, an inequality m the ! waves of red bloodwhich travel from right to left. Moreover, the diameters of the subclavian arteries on each side are different, that on the right being noticeably larger. _The left lobe of the brain,, therefore, being more richly hsematosed than the right, becomes stronger; and- as;- by the intersection of the nervous fibre, it commands the right side of the body, it is obvious that that side will be more readily controlled. This furnishes one reason for the natural preference for the right hand, and another is found m the 'increased supply of blood from the subclavian artery. The augmentation of blood we have alredy seen suggested; biiitth^ reason for it.is here v ;aseril)ed' i to;;fH"6/'relativ©'"Bize-.of the artery, and not to any directness; of path from the heart. r l} nl Eleury. has carried hisr investigations through the whole series of mammalia : and he finds that the 1 ; right-handed peculiarities exist m all that have' arteries arranged similar to those of man 1 . Alt the" same time; stich animals,, notably the champanzee, the : seals and the beavers, are the' 1 most adroit arid inteHigenti' ■ ;■ ' >; 'U : : },■ ; v ;