370 



EXPEEIMENTS ON CO-OPERATION. 



took a larva. 



At this time I went to bed. There were still about 

 twenty-five larvae in the cup, which had all been 

 removed when I looked at 6.15 the next morning 

 During the whole time she was under observation, only 

 two other ants found their way to the cup, though 

 there were some wandering about in the box all day. 

 Towards evening, however, they went into the nest, and 

 for some hours my ant was the only one out. It will 

 be observed that she returned at shorter intervals than 

 the previous ones. This was partly because she had a 

 shorter distance to go, and partly because she was not 

 bewildered by three cups, like the preceding. I had 

 placed a bit of wood to facilitate her ascent into the 

 cup. This she made use of, but instead of going the 

 shortest way to the cup, she followed the side of the 

 box, partly, perhaps, because the floor was covered with 

 a plate of porcelain. This, however, would not account 

 for the fact that at first she invariably went beyond the 

 cup, and even past the second cup ; gradually, however, 

 this circuit became smaller and smaller ; but to the 



