96 ANTS AND ANT LIFE. 



victims to them. When the ants have departed, the owners 

 come home again. If their hiding place is flooded by 

 a tropical rainstorm, the ants crowd closely together into a 

 large heap, take the younger and weaker in the middle, and 

 pass over the water till they reach a dry place. Over 

 smaller streams they form a living bridge when on the 

 march, by clasping each other firmly and so forming a chain 

 by which the host crosses. By help of such chains also they 

 let themselves down from trees. 



In South America there is a travelling, marching, or 

 foraging kind of ant, with exactly similar habits, about 

 which the English naturalist, Bates, in his " Travels on the 

 Amazon," has published a complete account, and of which 

 more will be said further on.* It is, however, a suitable 

 place for dealing more fully with another non-European 

 species, which has a special interest. It is the Bi-azilian 

 travelling or visiting ant, Mi/rmica, or Atta, or JEcodoma 

 cephalotes, sometimes called Sa-uba. They are usually 

 known by the name of umbrella-ants, because they are seen 

 marching in long crowded columns, each holding up between 

 its jaws a generally round bit of leaf, about the size of 

 a sixpence. They, however, do not use these bits of 

 leaf as sunshades, as was thought, but for roofing in and 

 covering their very extensive domed dwellings. The 

 Sa-iiba is a terrible plague, for it strips the most valuable 

 trees, namely the coffee-plants and orange trees, of their 

 leaves, and by its countless numbers makes agriculture al- 

 most impossible in some places. Lund relates that he one 

 day passed a tree in full leaf, and heard a patter like heavy 

 rain although the sky was quite clear. He went closer, and 

 saw an ant hard at work on every leaf-stalk. When the 

 leaf-stalk was gnawed through the leaf fell to the ground. 

 A still more remarkable scene was going on at the foot of 

 the tree. The ground was covered with ants, which seized 

 the leaves as they fell in heaps, and bit them in pieces. In 

 the space of an hour all was over. The tree was stripped, 

 the leaves cut up, the pieces carried away. The famous 

 traveller, Dampier (see " Bingley," p. 171)), saw similar trains 

 of these umbrella -ants, which, as he put it, looked like a 

 stream of moving pieces of leaves, under which the insects 



* [The migrating ants of Cayenne, the " Ants of Visitation " (Mme.. 

 Merian), and the Chasseur-ants of Trinidad, have similar habits. TK.] 



