Sensory Discrimination: The Chemical Sense 95 



ants are able to follow each other to supplies of food; or to 

 larvae, for an ant's behavior to an ant larva found in the 

 course of its wandering is like its behavior to food; the 

 larva is picked up and carried to the nest. Lubbock put 

 some larvae on a glass plate at a little distance from one of 

 his artificial ant nests, and set a similar empty plate beside 

 it ; he then made a bridge of a strip of paper leading from 

 the nest toward the plates, and connected each of them 

 with this bridge by a separate short paper strip. He placed 

 a marked ant at the larvae ; she picked up one and returned 

 to the nest. She soon appeared followed by several others ; 

 when she had reached the larvae, and before the others 

 had arrived at the dividing of the ways, Lubbock exchanged 

 the short strips, so that the one over which the marked 

 ant had passed now led to the empty plate. The following 

 ants all took this path, indicating that they were guided 

 by some trace which her footsteps had left. Lubbock was 

 inclined to think, however, that some kind of communi- 

 cation must have passed between the marked ant and her 

 fellows in the nest to induce them to follow her, and also 

 that this communication might on occasion convey some 

 notion of the quantity of food or larvae to be had. He 

 placed three glass plates near an ant nest, connecting each 

 of them with the nest by means of a paper strip. On one 

 plate he put a heap of several hundred larvae, on the second 

 two or three only ; the third was empty. He put a marked 

 ant on each of the plates, and captured all the ants which 

 they led back with them. Many more ants came to the 

 plate with the larger heap of larvae than to the others. 

 Lubbock explained this by supposing that the ant from that 

 dish had in some way communicated to the nest the greater 

 numbers at her disposal (441, pp. 172 ff.). Obviously 

 it would be enough to suppose that the smell of food or 



