246 WANT Of INGENUITY 



could ascend C, and, passing over d, descend upon the 

 larvse. I then put some specimens of Lasius niger to 

 the larvae, and soon a large number of ants were en- 

 gaged in carrying off the larvae. When this had con- 

 tinued for about three hours, I raised D ^ of an inch 

 above a. The ants kept on coming and tried hard to 

 reach down from d to a, which was only just out of 

 their reach. Two or three, in leaning over, lost their 

 foothold and dropped into the larvae ; but this was 

 obviously an accident ; and after a while they all gave 

 up their efforts, and went away, losing their prize, in 

 spite of most earnest efforts, rather than drop -j^ of 



an inch. 



Fig. 11. 



At the moment when the separation was made there 

 were fifteen ants on the larvae. These could, of course, 

 have returned if one had stood still and allowed the 

 others to get on its back. This, however, did not 

 occur to them ; nor did they think of letting themselves 

 drop from the bottom of the paper on to the nest. 

 Two or three, indeed, fell down, I have no doubt, by 

 accident ; but the remainder wandered about, until at 

 length most of them got into the water. After a time 

 the others abandoned altogether as hopeless the attempt 

 to get at the larvae. 



I waited about six hom-s, and then again placed the 



