Notices of New Books. 8541 



distance from any colony. Such heaps are always found to be removed 

 when the place is revisited the next day. 



"In course of time I had plenty of opportunities of seeing them at 

 work. They mount the tree in multitudes, the individuals being all 

 worker-minors. Each one places itself on the surface of the leaf, and 

 cuts with its sharp scissor-like jaws a nearly semicircular incision on 

 the upper side ; it then takes the edge between its jaws, and by a sharp 

 jerk detaches the piece. Sometimes they let the leaf drop to the 

 ground, where a little heap accumulates, until carried off by another 

 relay of workers ; but generally each marches off with the piece it has 

 operated upon, and as all take the same road to their colony the path 

 they follow becomes in a short time smooth and bare, looking like the 

 impression of a cart wheel through the herbage. 



" It is a most interesting sight to see the vast hosf of busy diminu- 

 tive labourers occupied on this work. Unfortunately they choose 

 cultivated trees for their purpose. This ant is quite peculiar to Tro- 

 pical America, as is the entire genus to which it belongs. It some- 

 times despoils the young trees of species growing wild in its native 

 forests ; but it seems to prefer, when within reach, plants imported 

 from other countries, such as the coffee and orange trees. It has not 

 hitherto been shown satisfactorily to what use it applies the leaves. 

 I discovered it only after much time spent in investigation. The leaves 

 are used to thatch the domes which cover the entrances to their subter- 

 ranean dwellings, thereby protecting from the deluging rains, the young 

 broods in the nests beneath. The larger mounds already described are so 

 extensive that few persons would attempt to remove them for the pur- 

 pose of examining their interior; but smaller hillocks, covering other 

 entrances to the same system of tunnels and chambers, may be found 

 in sheltered places, and these are always thatched with leaves mingled 

 with granules of earth. The heavily laden workers, each carrying its 

 segment of leaf vertically, the lower edges secured in its mandibles, troop 

 up and cast their burdens on the hillock ; another relay of labourers 

 places the leaves in position, covering them with a layer of earthy 

 granules, which are brought one by one from the soil beneath. 



" The underground abodes of this wonderful ant are known to be 

 very extensive. The Rev. Hamlet Clark has related that the Sauba 

 of Rio de Janeiro, a species closely allied to ours, has excavated a 

 tunnel under the bed of the river Parahyba at a place where it is as 

 broad as the Thames at London Bridge. At the Magoary rice-mills, 

 near Para, these ants once pierced the embankment of a large reservoir. 

 The great body of water which it contained escaped before the damage 



