Page:Principles of Psychology (1890) v1.djvu/93

73 FUNCTIONS OF THE BRAIN. 73 already went a good way in the same direction, showingj for example, that locomotion is a well-developed function of the medulla oblongata. But Sclirader, by great care in the operation, and by keeping the frogs a long time alive, found that at least in some of them the spinal cord would produce movements of locomotion when the frog was smartly roused by a poke, and that swimming and croaking could sometimes be performed when nothing above the medulla oblongata remained.* Schrader's hemisphereless frogs moved spontaneously, ate flies, buried themselves in the ground, and in short did many things which befora^ his observations were supposed to be impossible unless the hemispheres remained. Steinerf and Vulpian have re- marked an even greater vivacity in fishes deprived of their hemispheres. Vulpian says of his brainless carps| that three days after the operation one of them darted at food and at'a knot tied on the end of a string, holding the latter so tight between his jaws that his head was drawn out of water. Later, "they see morsels of white of egg; the moment these sink through the water in front of them, they follow and seize them, sometimes after they are on the bottom, sometimes before they have reached it. In captur- ing and swallowing this food they execute just the same movements as the intact carps which are in the same aqua- rium. The only difference is that they seem to see them at less distance, seek them with less impetuosity and less per- severance in all the points of the bottom of the aquarium, but they struggle (so to speak) sometimes with the sound carps to grasp the morsels. It is certain that they do not confound these bits of white of egg with other white bodies, small pebbles for example, which are at the bottom of the water. The same carp which, three days after operation, seized the knot on a piece of string, no longer snaps at it now, but if one brings it near her, she draws away from it by swimming backwards before it comes into contact with when the medulla oblongata is cut through just behind the cerebellum, f Berlin Akad. Sitzungsberichte for 1886. X Comptes Rendus, vol. 102, p. 90.
 * Loc. cit. pp. 80, 82-3. Schrader also found a biting-reQex developed