BEHAVIOR OF ANTS AND MYRMECOPHILES 401 



when the temperature was raised from ig° to 20 and 21 C. 

 The stimulus was assumed to be not simply heat, but a rise in 

 temperature. 



Experiments were made with ants in Fielde, aluminum and 

 Barth nests, and observations were made on outdoor' nests. 

 With the latter field notes were used, and ants engaged in vari- 

 ous activities were collected and the data recorded. The activ- 

 ities tested were 1, foraging; 2, partaking of different foods; 

 3, feeding themselves; 4, regurgitating to others and receiving 

 regurgitated food; 5, licking each other, likewise being licked; 

 6, tending the young; 7, building; 8, carrying other ants, like- 

 wise being carried; 9, surrounding the queen; 10, fighting; 

 11, responding to disturbances of the nest; 12, guarding; 13, 

 scavengering. 



An elaborate series of experiments was made, not only on 

 the relation of the size to the labor, but also in regard to age. 

 Callows, or recently hatched ants, acted chiefly as nurses, taking 

 no part in the defence of the colony or in building. The size of 

 the various workers was shown to be well correlated with the 

 activities, most of the work in the nest and the foraging being 

 done by the more active, smaller forms. The majors, both in 

 Camponotus and Pheidole, were ordinarily sluggish, but easily 

 stimulated by the nest's being disturbed, when they became 

 more active than the minors in defending the nest. This is 

 a valuable adaptation, keeping the majors in readiness and 

 reserve for fighting. Buckingham shows that workers and 

 even queens of various sizes participate to some extent in the 

 activities of the colony, but a preponderant number of those 

 working (with the exception of defending the nest, compara- 

 tively few of the ants in a colony are working at any one time) 

 showed distinctly that the functions of the ants of different 

 size are correlated with their structural differences. 



Champlain (3) records the capture of Xenodnsa cava in num- 

 bers in Connecticut, on tree tanglefoot which is used to trap 

 the fall cankerworm. Ants also had fallen victims. 



Cornetz (5, 6, 7, 8) and Cornetz and Bohn (11) in Algeria 

 studied the homing of several hundreds of individual ants. 

 Seven species were observed. An ant on going away from the 

 nest strikes out in a definite direction, which it maintains in a 

 general way throughout the out -going trip. From time to time 



