PREVIOUS OBSERVERS. 239 



Dr. Biichner records the following instance on the 

 nuthority of a friend (M. Theuerkauf) : — 



' A maple tree standing on the ground of the 

 manufacturer, VoUbaam, of Elbing (noiv of Dantzic") 

 swarmed with aphides and ants. In order to check 

 the mischief, the proprietor smeared about a foot width 

 of the ground round the tree with tar. The first ants 

 who wanted to cross naturally stuck fast. But what 

 did the next? They turned back to the tree and 

 carried down aphides, which they stuck down on the 

 tar one after another until they had made a bridge, over 

 which they could cross the tar-ring without danger. 

 The above-named merchant, Vollbaum, is the guarantor 

 of this story, which I received from his own mouth on 

 the very spot whereat it occurred.'' 



In this case I confess I have my doubts as to the 

 interpretation of the fact. Is it not possible that as 

 the ants descended the tree, carrying the aphides, the 

 latter naturally stuck to the tar, and would certainly 

 be left there. In the same way I have seen hundreds 

 of bits of earth deposited on the honey with which I 

 fed my ants. 



On one occasion Belt observed ^ a community of 

 leaf-cutting ants {(Ecodoma), which was in the process 

 of moving from one nest to another. ' Between the 

 old burrows and the new one was a steep slope. In- 

 gtoad of descending this with their biu-dens, they cast 



' Mind in Animals, by Prof. Ludwig Biichner, p. 120. 

 ' Naturalist in Nica/ragua, 0. Belt, p. 76. 



