288 MENTAL FACULTIES sec. 



to the cross-bar of the window. In this vessel the ants' food, 

 some crushed sugar, was placed, and in order that the ants 

 might be aware of the new position of the food provided for 

 them a number of individuals were placed in it. The busy 

 little creatures took up their crumbs of sugar, soon found their 

 way up the only means of communication, the suspending 

 thread, along the cross-bar and down the window-frame, and 

 reached their companions on the window-sill, to continue from 

 there their usual journey down the high wall to the nest in the 

 garden. It was not long before a regular traffic over the new 

 road from the window-sill to the store of sugar was organised, 

 and so a few days went by without offering anything novel. 

 But one morning the traffic ceased at its old terminus, and the 

 ants again obtained their groceries from a nearer source — 

 namely, from the window-sill. Not a single individual made 

 the journey thence to the vessel of sugar. Yet this had not 

 been emptied. By no means ; but a dozen individuals were 

 working vigorously and unweariedly in the vessel above, 

 simply carrying the grains of sugar to its edge and throwing 

 them down to their comrades on the sill below." 



P. Huber ^ made the following observation : He watched 

 an ant building a covered way out of earth : first it erected a 

 vertical wall on one side, then it raised a second vertical wall 

 parallel to the first, in order to support a roof on the two, and 

 so form the gallery. It had begun to extend the roof out 

 horizontally from the upper edge of the second wall ; appar- 

 ently it was intended to rest upon the first wall on the other 

 side, but this had been carried too high. Then a second ant 

 came by, looked at the defective structure, examined it, drove 

 the unskilful builder away, pulled down the walls, and built 

 the whole anew. 



P. Huber also records the followins^ observation in humble- 

 bees, which build their combs horizontally one over the other : 



^ p. Huber, Recherches, p. 47. 



