I will not attempt to detail these experiments—but merely state some of the results. For the many important facts that were discovered by them reference must be made to the valuable volume in which they are reported. He found the entire brain to be connected with the nerve system by the process of interlacing. Excitation of the right brain was shown by the left side of the body; of the left brain by the right side. So it was with the nerves of the senses. Whether the like structure exists in the duplex organ of the intelligence he could not trace, because the mental results were incapable of being expressed by experiment upon animals, who cannot tell us what are their emotions. But he entertains no doubt that the same structural scheme is observed in the action of the two hemispheres also. The great ganglia at the base of the brain, whether excited by electricity or destroyed by cautery, yielded the same result. They proved beyond doubt that _their_ function is to direct the actions of the body under the peculiar conditions of its duplex structure—that is to say, a formation by two distinct and not wholly similar halves joined together and requiring community of action. This process of separate action for each part combined with motion in _co-ordination_—that is to say, the regulation of the motions of the limbs, so that the two halves of which the body is builded may act in definite relationship—was found to be the special business of those basal ganglia, any disturbance in those ganglia being attended with imperfect movements of the body, even to the extent of causing the animal to walk in a circle, having lost entirely the power to “walk straight.” The results of this ingenious experiment are extremely curious and throw great light on the physiology of locomotion. The second division of the brain, lying in its centre, overlapped behind by the cerebrum, resting on the centres that direct bodily actions and dominated by the hemispheres that are the organs of the intelligence, is shown by these experiments to be the centre upon which the senses converge. To this common centre the impressions made upon the senses by the external world are conveyed. The experiments seem to indicate that a distinct ganglion is devoted to each sense, although all are united in one mass for the common purpose of reception of the information they bring. The destruction of different parts of this brain centre is found to be followed by the loss or impairment of different senses. It was found, also, that this part of the brain was duplex, like the other parts, for destruction of the right side of the ganglion caused paralysis of the senses on the left side of the body and _vice versâ_.