Some interesting conclusions follow from what has just been given. It is evident that after the first change in the location of the strings, these come to stand out from the other parts of the box; they are distinguished. They are singled-out-elements of a compound, and we seem to get some little beginnings of what in human minds is called "abstraction." But let me hasten to say that the reader must not think that such abstraction is conscious in at all the degree in which we find it in adult human behavior. As has been suggested above, and as will be shown later, the cause and effect relation probably never is felt or thought by these birds. All that is meant is that some one part, rather than a definite place to hop upon, gradually comes to be felt apart and thus impulsively to be worked with more than some other.
Series B. Male English Sparrow and Female Cowbird
These birds are those which have been with the female English Sparrow during all the previous tests. The male Cowbird had been removed much earlier for the reason that it cost the female Sparrow too much of her energy to fight with him.
It will be seen from the table below (Table III) that the rate of learning is very slow with these two birds. The times are often very long and the errors for the English Sparrow many. This is chiefly due to his extreme wildness, and were it not probable that this very wildness really plays into the hands of the experimenter the present series should be counted in large part as a failure.
It is possible that being so long accustomed to seeing the female English Sparrow open the door they now sit and wait. They have learned not to do instead of to do. Thus they fail in thirty minutes in the first trial and the door is opened in the second trial by accident. In the third the male Sparrow succeeds in thirty-one minutes after many trials. The manner in which the door was opened by him is of interest. The uncritical observer might call it imitation, for he flies out from the front upper edge, turns, and in his flight seizes the strings. This is very similar to the method of the female Sparrow, but I have had frightened Sparrows behave in this same way when they were alone with this box. Furthermore I have observed this reaction in the English Sparrow as it seized a feather or bit of other material in its free life out of doors.
In the fourth trial both fail in one hour. But this apparently negative result really means quite different behavior by each of the two birds. The amount of activity and therefore the energy expended by the Sparrow is enormously greater than that of the Cowbird. The former shows signs of knowing where to alight, though he cannot overcome his fright. The
