Page:Principles of Psychology (1890) v1.djvu/94

74 74 PSYCHOLOGY. her mouth." * Already on pp. 9-10, as the reader may re- member, we instanced those adaptations of conduct to new conditions, on the part of the frog's spinal cord and thalami, which led Ptiiiger and Lewes on the one hand and Goltz on the other to locate in these organs an intelligence akin to that of which the hemispheres are the seat. When it comes to birds deprived of their hemispheres, the evidence that some of their acts have conscious purpose behind them is quite as persuasive. In pigeons Schrader found that the state of somnolence lasted only three or four 'days, after which time the birds began indefatigably to walk about the room. They climbed out of boxes in which they were put, jumped over or flew up upon obstacles, and their sight was so perfect that neither in walking nor flying did they ever strike any object in the room. They had also definite ends or purposes, flying straight for more convenient perching places when made uncomfortable by movements imparted to those on which they stood ; and of several possible perches they always chose the most con- venient. "If we give the dove the choice of a horizontal bar (Reck) or an equally distant table to fly to, she always gives decided preference to the table. Indeed she chooses the table even if it is several meters farther off than the bar or the chair." Placed on the back of a chair, she flies first to the seat and then to the floor, and in general " will for- sake a high position, although it give her sufiiciently firm support, and in order to reach the ground will make use of the environing objects as intermediate goals of flight, show- ing a perfectly correct judgment of their distance. Although able to fly directly to the ground, she prefers to make the journey in successive stages. . . . Once on the ground, she hardly ever rises spontaneously into the air." f Young rabbits deprived of their hemispheres will stand, run, start at noises, avoid obstacles in their path, and give responsive cries of suft'ering when hurt. Rats will do the same, and throw themselves moreover into an attitude of defence. Dogs never survive such an operation if per- formed at once. But Goltz's latest dog, mentioned on p. f Loc. cit. p. 216.
 * Comptes Rendus de I'Acad. d. Sciences, vol. 103, p. 1530.