ANTS AND ANT LIFE. 99 



At a depth of about a foot and a half I found several 

 tunnels of a large marmot species, the terror of cocoa 

 planters, because in making their passages they gnaw off the 

 thickest roots of the cocoa plants. The interior of the ant 

 hill had apparently fallen in through these mines. Unfor- 

 tunately I was unable to follow further the progress of the 

 new building, for I was obliged to leave the next day for 

 Sao Juan del Sur. When I returned at the end of a week 

 the building was finished, and the whole colony was again 

 busy with the leaves of the coffee plants." 



The most detailed accounts of these remarkable ants are 

 given by H. D. Bates ('' The Naturalist on the River 

 Amazon," London, 1863). According to him, also, the 

 Sa-nba is a terrible pest in Brazil, and makes agriculture 

 impossible in many districts. Their workers fall into three 

 distinct classes, and vary in size from two to seven lines. 

 The domes of their nests, often forty yards in circumference, 

 rise only two feet from the ground, and guard the entrances 

 to their extensive underground galleries. These entrances 

 are generally closed, and are only opened under special cir- 

 cumstances. A large hollowed out chamber, of from four 

 to five inches in diameter, is found in the interior of the 

 nest. The habit of the Sa-uba of cutting off and carrying 

 away large quantities of leaves has long been known. The 

 columns then resemble a large mass of moving leaves. 

 Near their nests are found heaps of such rounded bits of 

 leaves, and these are always carried off on the following 

 day. Bates often saw them at work, and noticed that they 

 cut a half-circle in the upper face of the leaf with their 

 razor-like mandibles, and then pulled it away from the uncut 

 side by a sudden jerk. It was often thrown down to the 

 comrades waiting below, but as a rule each ant marched off 

 with its own piece. Cultivated trees attract them more 

 than any other. The leaves serve as roofs for their dwell- 

 ings and as a protection against tropical rains for their 

 young. Some of the laborers pull the leaves along ; others 

 put them in their right places and cover them with a layer 

 of earthy matter brought up from the depths of the nest. 



The Rev. H. McCook (toe. cit., 1879, p. 84) watched the 

 same kind of ants in Texas, where they are called Brazilian 

 or cutting-ants. Their trains seemed to him like a pro- 

 cession of Lilliputian Sunday-school children, carrying their 



