Stories by W. Grey Walter

By recording the pulsation of tiny currents from various parts of the head the electroencephalographer diagnoses brain disorders and studies the basic mechanism of mind

Concerning Machina docilis, descendant of Machina speculatrix, the small imitation of life that was described in the May, 1950, issue of this magazine

Concerning the author's instructive genus of mechanical tortoises. Although they possess only two sensory organs and two electronic nerve cells, they exhibit "free will"