1879.] NATURAL SCIENCES OF PHILADELPHIA. 155 



large double mound, his attention was attracted by a continuous 

 and peculiar rasping sound. This was produced by ants who were 

 scattered over the surface of the trunk engaged in scooping out 

 with their mandibles the bark thereof. The gray outer hark had 

 been removed in many places, and the reddish-brown bark beneath 

 cut awaj r so as to give the tree a marked spotted appearance. 

 The excavated portions covered a surface at times of two or three 

 square inches, and were from one-sixteenth to one-eighth of an inch 

 in depth. The pellets were sometimes allowed to accumulate in 

 the mandibles, but were generally rejected as soon as cut off, 

 and dropped to the earth. In only two cases was there any appli- 

 cation of the tongue to the bark. No other tree was observed to 

 be thus marked. The purpose of this curious behavior could not 

 be conjectured. 



The directness with which the foragers take the home path was 

 thus illustrated. One worker was seen by his companion, Mr. 

 Kay, to seize a small green insect, with which she immediately 

 turned homeward. She was followed patiently with her burden 

 to the nest, a distance of 126 feet, and her path upon measure- 

 ment was found to be a direct line. She was twice attacked upon 

 the route, once by several workers of the same species ; she hid 

 from these assailants beneath a leaf and waited until they dis- 

 persed. The second time she was assaulted by two workers from 

 whom she escaped by running. Once she rested for one half a 

 minute. A number of times she met foragers apparently of her own 

 nest, for after antennal salutations she passed peacefully on. The 

 direct line was in no case interrupted. 



In turning up a number of stones in the neighborhood of various 

 mounds, liosts of white ants, Termes flavipes, were uncovered, who 

 were instantly attacked by the roving exsectoides, and carried 

 off in their jaws. These termites evidently are preyed upon by 

 the mound builders. .Nests of small true ants, exposed in a simi- 

 lar way, were similarly dealt with. 



A sjreat number of abandoned and moss-grown mounds- were 

 seen here. In some cases, one part of the hill was occupied and 

 the other abandoned. In the unoccupied parts when washed out 

 by the rains, the exposed walls of the galleries presented a pretty 

 columnar appearance, which was made more striking by the over- 



covering moss. 



As the evening advanced attention was directed to the gates to 

 note if any attempt would be made to close them. Previous stu- 

 dies, made later in the summer, had failed to detect any such 

 effort. Five doors not far removed from each other upon the side 

 of a large mound, were put under close observation. These were 

 watched until the night was too far advanced to allow further 

 notice, at which time, three doors were quite closed and two 

 nearly so. There appeared to beaconflict of behavior on the part 

 of the workers, some carrying the pellets of earth quite out of the 



