82 ON THE HABITS OF ANTS. [LECT. 



This, however, appeared never to occur to them. At 

 length they gave up all attempts to reach up to the glass, 

 and went round by the long paper bridge. I left the 

 arrangement for several weeks, but they continued to do 

 the same. 



Again I varied the experiment, as follows : Having 

 left a nest without food for a short time, I placed some 

 honey on a small wooden brick, surrounded by a little 

 moat of glycerine, about half an inch wide and about T ^th 

 of an inch in depth. Over this moat I placed a paper 

 bridge, one end of which rested on some fine mould. I 

 then put an ant to the honey, and soon a little crowd 

 was collected round it. I then removed the paper 

 bridge ; the ants could not cross the glycerine, they came 

 to the edge and walked round and round, but were unable 

 to get across ; nor did it occur to them to make a bridge 

 or bank across the glycerine by means of the mould which 

 I had placed so conveniently for them. I was the more 

 surprised at this, on account of the ingenuity with which 

 they avail themselves of earth in constructing their 

 nests. For instance, wishing, if possible, to avoid the 

 trouble of frequently moistening the earth in my nests, 

 I supplied one of my ant-nests of Lasius flavus with a 

 frame, containing, instead of earth, a piece of linen, one 

 portion of which projected beyond the frame, and was 

 immersed in water. The linen sucked up the water 

 by capillary attraction, and thus the air in the frame was 

 kept moist. The ants approved of this arrangement, 

 and took up their quarters in the frame. To minimize 

 evaporation, I usually closed the frames all round, leaving 

 only one or two small openings for the ants, but in this 

 case I left the outer side of the frame open. The ants, 



