2o8 IMPORTANCE OF SCENT. 



thither from side to side between the nest and the 

 point A, and only after very repeated efforts around the 

 original site of the larvae reach, as it were accidentally, 

 the object desired at b. 



Another evidence of this consists in the fact that if 

 when ants (Z. nigei') were carrying off larvae placed in a 

 cup on a piece of board, I turned the board round so that 

 the side which had been turned towards the nest was 

 away from it, and vice versa, the ants always returned 

 over the same track on the board, and, in consequence, 

 directly away from home. 



If I moved the board to the other side of ray 

 artificial nest, the result was the same. Evidently they 

 followed the road, not the direction. 



In order further to test how far ants are guided by 

 sight and how much by scent, I tried the following ex- 

 periment with Lasius niger. Some food was put out at 

 the point a. on a board measuring 20 inches by 12 (Fig. 

 Fig- 18- 18), and so arranged 



— that the ants in going 



I'' 



ri 



III 

 11 

 11 

 1^1 



straight to it from the 

 nest would reach the 

 board at the point 6, 

 and after passing under 

 a paper tunnel, c, would 

 proceed between five 

 pairs of wooden bricks, each 3 inches in length and l-j[- 

 in height. When they got to know their way, they went 

 quite straight along the line d e to a. The board was 



