486 PROCEEDINGS OF THE AMERICAN ACADEMY- 



five minutes' duration. Sometimes ants of this species were captured 

 and preserved in alcohol and then mounted in series, as described 

 above for Camponotus (p. 469). Eighteen colonies were studied. 



2. Observations. 



1. Field notes. — In these studies, as in those on Camponotus pictuSy 

 certain activities were not recorded. This was due to the fact that, 

 for the most part, these activities are carried on below ground, and 

 hence are not to be seen without disturbing the nest. 



In regard to the other activities, it appeared that here as in Cam- 

 ponotus pietus when studied in the field, the proportion of ants engaged 

 in any activity at one time was very small in relation to the total 

 number of ants belonging to the colony. On the whole, the minors are 

 much more alert in all activities, it being only rarely that the soldiers 

 take any part at all. Thus, carrying food, tending the young, carrying 

 other ants, fighting and scavengering are functions in which only the 

 minors take part; while in other duties (foraging, cutting up meal- 

 worms, carrying earth, and being carried), though both classes partici- 

 pate, the minors exhibit the greater activity. I have never seen the 

 soldiers eating in the field. There is, moreover, no function which 

 belongs exclusively to the soldiers. The question is whether there is 

 any function to which this class is exclusively adapted. Wheeler 

 (•'02, p. 770) says that in Pheidole, the soldiers of the grain-storing 

 species crush seed, breaking up the hard shells, while those of the 

 carnivorous species cut up the hard chitinous joints of insects. He 

 states that, in some species, the soldiers deserve their name, while in 

 others they are cowardly. I have never seen Pheidole piUfera in the 

 field tearing seeds apart or crushing them. As to cutting to pieces 

 large insects, I have frequently seen the soldiers pass by large insects 

 which they found in the field, or the meal-worms which I placed near 

 the entrances of the nests, whereas the same food was frequently 

 carried in by the minors, either in separate bits or as a whole, by the 

 combined action of a number of ants. Only once have I seen a soldier 

 engaged in cutting up an insect. On this occasion I placed a meal- 

 worm, which was dry and had been partly eaten by its comrades, near 

 the entrance of the nest where many minors were going and coming. 

 Almost immediately two minors began to feed on it, and others soon 

 joined them. After five minutes, when one had eaten, it entered the 

 nest, and almost immediately a number of other minors emerged and 

 began to eat the meal-worm. Then they began to break off bits of the 

 insect and to carry it into the nest. All the ants which emerged fi"om 

 the entrance now went to the meal-worm. After fifteen minutes the 



