25 



average distance of the ants from the outside edge of the sand was 

 one and an eighth inches, but the nearest ants were in an approximate 

 circle around the sand at a distance of five-eighths of an inch. (Fig 3.) 



Fig. 3 



Experiment 5771, Oil of Lemon. — January 12, 4: 15 p. m. A lit- 

 tle sand moistened with oil of lemon was placed on the base, and the 

 orange cover was moved to bring its center over the sand. Within 

 three minutes nearly all the ants were out from under the cover, leav- 

 ing nearly all their larvae behind. A few of the latter which were so 

 far from the sand that the ants could get at them, were brought to- 

 gether near the edge of the nest. Some of the ants attempted to re- 

 move the remaining larva, but when they came within an inch and a 

 quarter to an inch and a half of the sand they stopped, sometimes 

 with spasmodic jerkings of their antennae, and then turned back. 



A larger orange cover, 4X5 inches, was placed over the sand and 

 left over night. 7:10 a. m. (14 hours, 55 minutes), no ants under the 

 cover, all being gathered along the edge of the base. The larvae were 

 still scattered about in the nest. 8 a. m., orange cover replaced by an- 

 other, 5 X 6 inches. 9 a. m., the ants would not go under the cover 

 except that an occasional one ran in for a moment at the edge. A still 

 larger glass, 6 X 8 inches, substituted for the preceding. 11 : 30 a. m., 

 the ants were all under one end of the cover, as far away as possible 

 from the sand, but they had not gathered up their scattered larvae. 

 The position was as shown by the following sketch (Fig. 4). The 

 ants nearest the center of the nest were constantly moving about, as 

 if dissatisfied, those nearer the edge being quiet. The large cover was 



