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THE POPULAR SCIENCE MONTHLY.
Büchner, in his recently published and translated work on "Mind in Animals," gives a singular observation analogous to the above, which was communicated to him by Herr G. Theuerkauf. A maple tree standing in the grounds of Herr Vollbaum, of Elbing, swarmed with ants and aphides. In order to check the mischief, the proprietor smeared about a foot width of the ground around the tree with tar. The first ants that arrived stuck fast; but the next, seeing the predicament of their companions, turned back and fetched a number of aphides from the tree, which they stuck down on the tar one after another till they had made a bridge over which they could cross without danger.
It will be observed that all these cases, being so analogous although recorded independently by different observers, serve to corroborate one another. As such corroboration in matters of this kind is of value, I shall here add two or three cases which go to confirm the observation of Cardinal Fleury regarding the construction of a floating bridge. Dr. Ellendorf writes to Professor Büchner that he protected a cupboard of his provisions from the invasion of ants by standing the legs of the cupboard in saucers filled with water. He adds:
The military ants, both in America and Africa, exhibit still more extraordinary resources in the way of bridge-making. Thus Belt says of the Ecitons: