Note 25 — CAUSES OF IDIOCY.

At a meeting of the Medico-Psychological Society of Paris, my friend M. Auguste Voisin exhibited plates of the brains of idiots who had only begun to speak at the age of from three to five years, in which the frontal and first parietal convolutions were rectilinear without secondary folds, resembling the fœtal condition of the convolutions at the sixth month of intra-uterine life.