Author : Le Bon Gustave
Title : On the Inequality of the Corresponding Regions of the Skull
Year : 1878

Link download :

Messieurs, during my studies that I have pursued for a long time concerning the variations of the brain’s size and shape that one observes among individuals belonging to the same race—studies whose findings I intend to soon entertain you with—I have had occasion to investigate whether the different parts of the cerebral hemispheres on the right side and on the left side habitually possess the same size. Not being able to easily obtain a determination of the weight of the brain and its associated parts, I was obliged to effectuate my research upon the skull itself. My measurements have been taken on nearly 300 skulls belonging to different series in the collection of the Museum of Anthropology, which were graciously placed at my disposal by Doctor Broca. For a long time anatomists have wondered whether the two cerebral hemispheres are quite alike. The most widely-held opinion has been that of Bichat, who considered that a lack of symmetry of these organs must be accompanied by a lack of sound judgment. The autopsy of this famous anatomist, whose own skull proved to be most irregular, demonstrates how little this opinion is well-founded. With man, the majority of the organs are generally more developed on the right side than on the left; but, considering that the left portion of the brain presides over the functions of the right part of the body, one might deduce that it is the left hemisphere of the brain which must be the most developed. A professor in Bordeaux, Doctor H. Fleury, recently affirmed a similar opinion, based on his contention that blood circulation is more active in the brain’s left hemisphere than in the right hemisphere, because of the dissymmetrical divisions of the aortic arch. ...