FORAGING ANTS 



469 



Foraging Ants, — Many confused statements have been 

 published in books of travel, and copied in Natural 

 History works, regarding these ants, which appear to 

 have been confounded with the Saiiba, a sketch of whose 

 habits has been given in the first chapter of this work. 

 The Saiiba is a vegetable feeder, and does not attack 

 other animals ; the accounts that have been published 

 regarding carnivorous ants which hunt in vast armies, 

 exciting terror wherever they go, apply only to the 

 Ecitons, or foraging ants, a totally different group of this 

 tribe of insects. The Ecitons are called Tauoca by the 

 Indians, who are always on the look-out for their armies 

 when they traverse the forest, so as to avoid being at- 

 tacked. I met with ten distinct species of them, nearly 

 all of which have a different system of marching ; eight 

 were new to science when I sent them to England. Some 

 are found commonly in every part of the country, and 

 one is peculiar to the open campos of Santarem ; but, as 

 nearly all the species are found together at Ega, where 

 the forest swarmed with their armies, I have left an 

 account of the habits of the whole genus for this part 

 of my narrative. The Ecitons resemble, in their habits, 

 the Driver-ants of Tropical Africa ; but they have 

 no close relationship with them in structure, and 

 indeed belong to quite another sub-group of the ant- 

 tribe. 



Like many other ants, the communities of Ecitons are 

 composed, besides males and females, of two classes of 

 workers, a large-headed (worker-major) and a small- 

 headed (worker-minor) class ; the large-heads have, in 

 some species, greatly lengthened jaws, the small-heads 

 have jaws always of the ordinary shape ; but the two 

 classes are not sharply-defined in structure and function, 

 except in two of the species. There is, in all of them 

 a little difference amongst the workers regarding the size 

 of the head ; but in some species (E. legionis) this is not 

 sufficient to cause a separation into classes, with division 

 of labour ; in others (E. hamata) the jaws are so 

 monstrously lengthened in the worker-majors, that 

 they are incapacitated from taking part in the labours 

 which the worker - minors perform ; and again, in 

 others (E. erratica and E. vastator), the difference is so 

 great that the distinction of classes becomes complete, 

 one acting the part of soldiers, and the others that of 



