Page:Popular Science Monthly Volume 58.djvu/530

522 A record of the route in connection with the time of the trip is necessary as an index of the effect of experience, because if the animal takes a direct course, with no wrong turns, but makes several halts, the time may indicate no profiting by the former acts, whereas the route will at once show that there has been improvement. Thus one record supplements the other.

These experiments were made six or eight times a day until fifty trials had been given. The tenth trip was made in three minutes five seconds, with two mistakes in turning. The time of the twentieth journey was but forty-five seconds, and that of the thirtieth, forty seconds. In the latter experiment a direct course was taken; this was also true in the case of the fiftieth trip, which was made in thirty-five seconds. Fig. 3 represents graphically the times of the first twenty experiments of this series. The vertical

column of figures at the left, 1 to 40, indicates minutes; the horizontal line of figures, 1 to 20, gives the number of trials.

That the turtle profited by experience, and that very rapidly, is evident from the figures. The average time for the first ten trips, from one to ten, was eight minutes fifty-four and a half seconds; the average time of the ten trips between thirty and forty was one minute three seconds. What at first took minutes, after a few trials required only as many seconds. There was remarkably little aimless wandering, crawling up the sides of the box and sulking in the corners after the third experiment. In fact, the animal soon began to behave as if it had the goal in mind and was intent on making directly for it. It learned with surprising quickness to make the proper turns and to take the shortest path. Three or four times I noticed it turn in the wrong direction, crawl into a corner and, as it seemed, become confused, for it then