BUCKINGHAM. — DIVISION OF LABOR AMONG ANTS. 427 



different classes. Probably this is largely due to t.he fact that the 

 observations were in many cases made upon different species. There 

 are, however, certain facts regarding the existence of classes which 

 seem to be established by previous observations. 



Different classes certainly exist in various species of ants; but the 

 division into classes is not sharp in all species in which they are 

 present. 



Where structural differences are not well defined, there is not a 

 sharp distinction in function : For example, classes 1 and 2 of Anomma 

 (Savage, '47, p. 5) ; some species of Eciton (Bates, '92, p. 355 ; Belt, '88, 

 p. 357) ; different sizes of workers other than soldiers in Holcomyrmex 

 (Wroughton, '92, p. 15) ; some species of Camponotus (Pricer, =08, 

 p. 192). 



In those species where the classes are well defined, the small workers 

 are generally admitted to be the real workers. In Anomma they en- 

 gage in carrying pupae and prey (Savage, '47, pp. 5-11 ; '50, p. 197) ; 

 in Eciton crassicornus and E. vastator, in repairing the nest, and in 

 E. hamata and E. mexicana, in marching beside the column (Bates, 

 '92, p. 362 ; Belt, '88, p. 22 ; Sumichrast, '68, pp. 43-44) ; in Atta, in 

 the charge of the "razzias" (Sumichrast, '68, p. 44) ; in ^. sexdens, in 

 tending queen larvae and leaf-cutting (Forel, '97, p. 331) ; in ^. cepha- 

 lotes, in leaf-cutting (Forel, 1. c.) ; in ^. structor, in carrying in seeds 

 (Moggridge, '73, p. 49) ; in ^. fervens, in leaf-cutting (Wheeler, :01% 

 p. 200) ; in Solenopsis, in constructing covered ways (Rothney, '89, 

 p. 366) ; in Pheidologeton laboriosus, in being in the open, fighting, 

 making covered ways (Rothney, '89, p. 369) ; in Pheidole megacephala, 

 in attacking prey, carrying home prey (Heer, '52, p. 3) ; in P, instahi- 

 lis, in foraging, excavating, caring for the brood, assisting callows to 

 emerge (Wheeler, :07^, p. 4) ; in Pheidole in general, in fighting, going 

 into the field, feeding the majors (Wheeler, :02, p. 770) ; in Holcomyr- 

 mex, in harvesting grain (Wroughton, '92, p. 15) ; in (Ecophylla sma- 

 ragdina, in carr)dng larvae for shuttles (Doflein, :05, p. 502) ; in 

 Camponotus, in fighting outside the nest (Forel, '74, p. 354) ; in Cam- 

 ponotus Ugniperdus, C. herculeanus, and C. puhescens^ in carrying 

 larvae and pupae (Forel, 1. c.) ; in Myrmecocystus, in fighting (Esche- 

 rich, :06, p. 46) ; in Formica sanguinea, in all the domestic duties 

 (White, '95, p. 67). 



In regard to the functions of the large workers, there is evidence 

 that they engage in a variety of occupations, but in some cases there 

 is a great difference of opinion as to what they do. For example, in 

 most species they appear to be for defence, since they are thus reported 

 for Anomma (Savage, '47, p. 5 ; '60, p. 197) ; Eciton erratica, E. vasta- 



