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large as our cent piece, and carry them away, presumably to use 



them in the construction of their dwellings. This species of ant 



IS named leaf-cutter and is known to be the greatest enemy to 



vegetation in the tropics. It chooses, for the most part, plants 



f not indigenous to the country. From this fact the author sees a 



result of natural selection, as only such plants could continue to 



hve and flourish which were not visited by these destructive ants. 



There arc many other species of ants found there, among 



which is a kind extremely hostile to the leaf- cutters. It is found 



that wherever these ants have taken possession of a tree, the 



leaf-cutters are driven away or hindered from attacking the tree, 



and the result is a flourishing growth, while those trees lacking 



this protection are injured and stunted by the destruction of their 

 leaves. 



It has long been known that certain plants in the tropics were 

 inhabited by ants, and the idea entertained that a mutual benefit 

 was thereby attained. The previous observations lacked definite 

 proof, but those more recently made by Schimper he believes 



ry 



9J> 



ited by ants extremely hostile, not only to their leaf-cutting 

 neighbors, but to any other disturber of their habitation. A 

 sharp stroke given to the tree w^as sufficient to call out a large 

 number of these ants, whose bite was extremely poisonous, and 

 the person rash enough to venture this experiment was glad to 



escape. 



Fritz Miiller describes the manner of the development of 

 these ant colonies as follows: The ant who is to become queen 

 mother of the colony bores or eats her way into the hollow stem 

 of the tree. The opening thus made is shortly afterward- closed 

 np by the growth of the surrounding tissues, and not only this, 

 but there is a farther development of abnormal tissue at this 

 place, which is filled with a nourishing sap for the food of the 

 ^nt She lays her eggs in the cavity of the stem, from which 

 ^I'e hatched the working ants, who soon open another communi- 

 cation With the outer world. 



Schimper found that the trees containing these ants were 



never disturbed by the leaf-cutters, while other trees of the same 



