APPENDIX, 251 



occur both in the forest and in the open. The commonest 

 species is the Atta {Acromyrmex) discigera, Mayr, and the 

 workers are never more than 6.5 mm. long. There are 

 other species of Atta which have very similar streets; 

 one, the Attn hystrix, Latr., appears to work only at night. 

 A minute description is given of a street of A. discigera, 

 which was 26 metres long and about 1.5 cm. wide and 

 high, roofed in in parts wherever possible. It led to a 

 number of small Cupheas, whose leaves the ants were 

 cutting. In the street could be seen a procession of 

 loaded ants going towards the nest, and others empty- 

 handed, going in the opposite direction. Some of the 

 large workers run up and down the road unloaded, and 

 act as road-menders if any accident happens to a part of 

 the track. Other very small workers, which do not cut 

 leaves, may also be seen carried upon the backs or even 

 upon the loads of the actual leaf-cutters. An ant carrying 

 a peculiarly shaped piece of leaf was watched from end to 

 end of the track, and travelled the 26 m. in 70 minutes. 

 The load was twice as heavy as itself. 



The plants attacked by the ants were found to be very 

 numerous, and the ants seemed to be very capricious in 

 this respect, one day stripping a plant and the next day 

 leaving it untouched. 



The jaws of the ants are very strong, with serrated edges, 

 and clash together laterally. The ant begins at the edge of 

 a leaf, and cuts out a piece in about five minutes, revolving 

 on one of its hind legs as a centre. When the piece is 

 almost freed, the ant goes on to the main portion of the 

 leaf, cuts through the last piece uniting it with the severed 

 portion, drags up the latter, balances it on edge between its 

 forelegs, and then, grasping it with its jaws, lifts it up above 

 its head, so that the centre of gravity of the load is above the 

 ant itself. It then marches off, down the stem, to the base, 

 over the ground to the end of the street, and along this to 

 the nest, travelling at a very uniform speed, and never 



