428 PROCEEDINGS OF THE AMERICAN ACADEMY. 



tor, E. crassicornus (Bates, '92, pp. 355 and 362), Pheidole megacephala 

 (Heer, '52, p. 3), P. pallidula (Forel, '74, p. 384), P. instabilis (Wheeler, 

 :07^ p. 4), Pheidole in general (Lubbock, '77 ; '79, p. 69 ; '82, p. 20 ; 

 but Wheeler, :02, p. 770, says that in some species of this genus they 

 are cowardly), Pogonomyrmex (McCook, '79, p. 196; Wheeler, ••05<^, p. 

 384), Camponotus (Forel, '74, p. 354 ; McCook, '76, p. 286 ; Alcott, '97 ; 

 Liiderwaldt, :09, p. 311), Formica sanguinea (White, '95, p. 67), Atta 

 (Forel, '97, p. 331 ; Wheeler, :07^ p. 675; Belt, '88, p. 83), (Ecophylla 

 (Dotlein, :05, p. 502), and Formicoxenus nitidulus (Forel, '86, p. 132). 

 They are said to form arches with their bodies in Anomma (Savage, 

 '47, p. 5) ; to march beside the column in Anomma (Savage, 1. c. ; '50, 

 p. 197), Eciton drepanophora (Bates, '92, p. 360), E. Jiamata (Belt, '88, 

 p. 22), and Atta fervens ; to perform some sort of guard duty in Eciton 

 mexicana (Sumichrast, '68, pp. 43-44), Pheidole (Reichenbach, '96, p. 

 xcv), Pogonomyrmex (McCook, '79, p. 196), and especially Colobopsis, 

 the wood borers (Forel, '96, p. 486), in which the soldiers close the 

 entrance of the nest with their heads and allow no strangers to enter 

 (Escherich, :06, p. 46 ; Forel, '86, p. 132 ; :03, p. 83 ; :05, pp. 453-454; 

 Wheeler, :04% p. 44; :10, pp. 182, 211-212; :05'; Lubbock, '82) ; to 

 attack prey in Anomma (Savage, '47) ; to cut up prey or seeds in 

 Pheidole (Heer, '52; Reichenbach, '96; Wheeler, :02, p. 770; :10, p. 

 279 ; :07^ p. 4), Aphaenogaster and Pogonomyrmex (Forel, '86, p. 132) ; 

 to attend to various aspects of building in Eciton mexicana (Sumi- 

 chrast, '68) and Pheidologeton (Rothney, '89, p. 369) ; to care for the 

 young in Eciton and Myrmecocystus (Escherich, :06, p. 46) ; to grind 

 leaves in Atta cephalotes Forel, '97, p. 331) ; to cut grass in Pogono- 

 myrmex (McCook, '79, p. 22) ; to carry seeds in Atta structor (Mog- 

 gridge, '73, p. 49) ; to carry out refuse in Camponotus (Pricer, :08, p. 

 192) ; to pull the edges of a leaf together in mending the nest in CEco- 

 phylla (Doflein, :05, p. 506) ; to perform in general the severer duties 

 of the colony in Formicoxenus (Forel, '86, p. 132) and Pogonomyrmex 

 (McCook, '79, p. 22) ; to become repletes in Myrmecocystus (Wheeler, 

 :08^ p. 378) ; to lay eggs in Aphaenogasta fulva (Fielde, :01) and in 

 Camponotus (Pricer, :08). 



As examples of difference of opinion held by competent observers 

 as to the function of the large workers in the same species, the follow- 

 ing may be cited. In Atta they are thought by Bates to be passive 

 defenders of the rest of the colony, but Wheeler contends that they 

 are aggressive soldiers. In Pheidole generally they are thought by 

 Lubbock to be fighters, but Wheeler states that, while in some species 

 of this genus they are for defence, in others they are not. 



In certain species there seems to be a third class, which is in size 



