Architecture in the Animal Kingdom. 131 



contains any facts belonging to this class of psycho- 

 logical actions. 



Patrons of animal intelligence have repeatedly 

 maintained, that ants build bridges with the intelligent 

 purpose of overcoming obstacles placed in their way. 

 Even a century and a half ago it was noticed by 

 Cardinal Fleury, that when he tried to keep ants from 

 climbing a tree by smearing it with bird-lime, they 

 gradually covered the bird-lime with earth and thus 

 paved a road across. He informed the famous Reau- 

 mur of this observation, who immortalized it in his 

 Memoires pour servir a 1'histoire naturelle des Insectes 

 (1734-1742). And because ants have not become 

 weaker-minded since the days of Reaumur, many 

 other friends of nature had the occasion, from that 

 time on, to observe and to record similar "bridges" 

 built by these insects. One of these reports, best 

 known in recent times, is the following. 1 Professor 

 Leuckart in Giessen (Germany) wishing to keep ants 

 from frequenting a certain tree, surrounded it with a 

 cloth soaked in tobacco- juice. The ants above the 

 cloth upon meeting the impediment turned back and 

 after awhile let themselves drop to the ground from 

 the branches, but those which were ascending to visit 

 the aphides, after having in vain tried to cross the ill- 

 smelling cloth, descended and after a short time were 

 seen coming back, each with a pellet of earth in its 

 mouth. These they pasted over the tobacco- juice, and 

 soon a passable road was constructed. William Mar- 

 shall recording this observation of Leuckart in his 

 "Leben und Treiben der Ameisen" (p. 40) adds the 



Buechner, "Geistesleben der Thiere," p. 116. 



