Page:Popular Science Monthly Volume 44.djvu/622

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clay for their labors. Later, when the rains come, they serve as drains to carry off the water which might threaten to invade the dwelling.

Comparative anatomy has long since removed the barriers, once thought impassable, raised by human pride between man and the other animals. Our bodies do not differ from theirs; and, moreover, such glimpses as we are able to obtain allow us to conclude that their psychic faculties are of the same nature as our own. Man in his evolution introduces no new factor.

The industries in which the talents of animals are exercised demonstrate that, under the influence of the same environment, animals have reacted in the same manner as man, and have formed the same combinations to protect themselves from cold or heat, to defend themselves against the attacks of enemies, and to insure sufficient provision of food during those hard seasons of the year when the earth does not yield in abundance.

It must only be added, to avoid falling into exaggeration, that man excels in all the arts, of which only scattered rudiments are found among the other animals; and we may safeguard our pride by affirming that we need not fear comparison. If our intelligence is not essentially different from that of animals, we have the satisfaction of knowing that it is much superior to theirs.



THE question "Why are we right or left handed?" has exercised the speculative ingenuity of many men. It has come to the front anew in recent years in view of the advances made in the general physiology of the nervous system; and certainly we are now in a better position to set the problem intelligently and to hope for its solution. Hitherto the actual conditions of the rise of "dextrality"—as the general fact of uneven-handedness may be called—in young children have not been closely observed. It was to gain light, therefore, upon the facts themselves that the experiments described in the following pages were carried out.

My child H—— was placed in a comfortable sitting posture, the arms left bare and free in their movement, and allowed to reach for objects placed before her in positions exactly determined and recorded by a simple arrangement of sliding rods. The experiments took place at the same hour daily for a period extending from her fourth to her tenth month. These experiments were