of the knots on the strings," those of the Sparrow as "pulls of the string."
In the 53rd test there occurred a change in the method of the Sparrow that should be of much interest to all students of animal and child life. Instead of using any of the methods he had up to this time employed he now alighted near the free side of the door and two-thirds the way to the top and struck the top string with his beak. A better way to express this
_Fig_10.jpg)
Fig. 10
The male Sparrow using his combination method. His fear seemed to be one of the chief incentives for this change from that shown in Fig. 9.
would be to say that after many attempts he succeeded in opening the door in this way. Fig. 11. In reality this method is to be designated as a combination of, at least, two of his previous methods. The writer would not have any one believe that this was a conscious invention on the part of this bird. He rather hastens to point out that such is very probably not the case. But neither are the first inventions of children consciously made. In fact such inventions as Professor Baldwin has cited and explained seem to be for the most part very similar to what is here recorded for the English Sparrow.
It was true many times that the female Cowbird did not come down at all until the door was opened. The Sparrow thus continued to open the door. A female English Sparrow was turned into the cage on the 77th test and a little later still another one. They served to distract him since he tended to follow them in their running around the box. If anything his fear which was constantly increasing was enhanced by their presence.
After the 100th trial the strings were changed to the left of
