40 



periment began was replaced. The sand seemed to have about as 

 much odor as at first. The ants, however, began to move under slowly, 







;^^v;^;;^v;>. 



".■>:; Deserted Lar\/Ae 



Fig. 17 



and at 10:30 April 20, some three-fourtlis of them were in the nest. 

 Experiment closed. 



Ants and ,;V%> 



9 



'^m' 



\ 

 \ 



4- 



Deserfed Larvae 



Fig. 18 



Experiment 5752. Carbon Bisulfid. — March 26, this material, ap- 

 plied as usual, drove the ants immediately out of the nest, but owing to 

 its volatility it soon lost its effect, and two hours and twenty minute? 

 later they were practically all back, continuing, however, to avoid the 

 immediate vicinity of the sand for several days. 



