IV.] 



METHOD OF FINDING THEIR WAY. 



127 



way, they went quite straight along the line d e to a. 

 The board was then twisted as shown in Fig. 51. The 



FIG. 51. 



bricks and tunnel being arranged exactly in the same 

 direction as before, but the board having been moved, 

 the line d e was now outside them. This change, how- 

 ever, did not at all discompose the ants ; but instead of 

 going, as before, through the tunnel and between the 



FIG. 52. 



rows of bricks to a, they walked exactly along the old 

 path to e. 



I then arranged matters as before, but without the 

 tunnel and with only three pairs of bricks (Fig. 52). 

 When an ant had got quite used to the path d to e, I 



