In M 1 out of 2.
In N 1 out of 3.
In G 1 out of 3.
Experiments with Chicks
The apparatus was as follows:
Fig. 15. Fig. 16. Fig. 17.
P was simply a small pen arranged with two exits, one leading to the inclosure where were the other chicks and food, one leading to another pen with no exit. The drawing ([Fig. 15] on this page) explains itself. A chick was placed at A and left to find its way out. The walls were made of books stuck up on end.
Q was a similar pen arranged so that the real exit was harder to find. (See [Fig. 16].)
R was still another pen similarly constructed, with four possible avenues to be taken. (See [Fig. 17].)