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Show CAUSE OF LEFT-HANOEDNESS. A AaaUimleal Kiplaiwllna for That Uualllv la the KfM. . II It a well-known fart the ttrnngei activity of the nerves of the right hall of the body (for not only the hand Ii concerned) must be ascribed to a preponderance pre-ponderance of Ih left side of thi hrsln, whose finer development, especially espe-cially as tne seat ot the center ot spserh. Is a matter of common knnwl etlfe. In a paper by Dr. Luddcckeni In th Algemelnes Journal der Uhr niorlinrkunst valuable Information regarding re-garding th two hemispheres of thi brain Is furnished. A sketch touch Av on th history of evolution leadi from the original symmetry of thi organism to s subsequent symmetrica' arranguuent of the heart and thn largi blood vccscla, from which It follnwi quite uslurally that the two halves ol th head are not placed on an equal fcKit.-tg as n-garda the distribution ol th blood, and consequently of th blood pressure: and that, on th contrary, con-trary, there must be, under normal cnndltinns, a strong pressure on thi arteries of the left side of tha bead. Thla theory 1 born out by well-known well-known experience ot anntomlatii and pathologists aaya Ih Indon L Mi rem, and a series of interesting observations. observa-tions. Ot especial Interest la the effect ef-fect nf the higher blood pressure upon tha left eye. Dr. Luddeckens found In ths latter, aa compared with tha right one, In a aurprlalngly large number uf caaea, a narrow pupil In consequence of a mora filled-up condition of tin Teasel of th Iris snd upon closer ex- ralnatlon a aborter construction ol th eyeball. Thla furnishes re-.jon tor th fact that In a larga number of person the left eye la tho better one. Thua the finer development ot the left half of the brain la explained very almply by the fact that It It belter supplied sup-plied with blood. Slid the question why It Is the seat of the renter of spoeeh snd why most people are right-handed Is solved In the must natural manner. |