1910] 



BunHI, Hon: Sanguinary Ants Changs Direction. 127 



cutting off an oblique-angled turn as shown (Fig. I, a). Again, 

 I noted that the messengers (special messengers in the sense that 

 their speed and other motions differed from the majority) who, as 

 later observations showed, were evidently hurrying back for rein- 

 forcements, '"did not stop at the captured nest but cut 'across lots' 

 slightly and started on the run home." Thus both those reinforce- 

 ments coming from the home nest laid out quickly a new trail, — 

 a curved hypotenuse to the oblique angled triangle of which the 

 captured nest was the apex,— and also the returning messengers 

 cut off even more, making a more nearly straight hypotenuse 

 (Fig. i, line a). 



The second example, Aug. 6, 1900: While the soldier nest 

 cited above was undergoing a swarming of sexed ants (appar- 

 ently only winged females), another nest of the same variety, 

 F. subintegra, some dozen meters northeast of the above nest, sent 

 a foray south across the lawn at 9 130 a.m., to the region just beyond 

 (south, Fig. 1, b.) a sugar maple; but by noon, most of the reds 

 had returned without any sign of an attack being made. At 4 130 

 p.m., the same route was again thronged, only they did not go so 

 far, staying more on the hither side of the maple (north and east. 

 Fig. 1, 3.) with their advance spread out over 5 or 6 square meters. 

 Fifteen minutes later: suddenly, with nervous jerks they concen- 

 trated in a compact mass rushing west, a direction at right angles 

 to the end of the main trail, and continued for over 60 cm. where 

 they concentrated about four or five captured blacks. During the 

 five minutes occupied by this shifting of the advance, I found, 

 about a meter beyond them, an inconspicuous black colony into 

 which nervous blacks were hurrying. 1 presume that the foraging 

 trail of these blacks to the maple had given by scent the secret of 

 the direction of their nest to the soldiers, who, as noted at 9:30 

 a.m., had been baffled in trying to locate blacks caught about the 

 tree. To continue the narrative of the advance, the soldiers began 

 to leave the captured blacks and work onward excitedly. Xot five 

 minutes elapsed before this new advance covered the remaining 

 distance to the inconspicuous nest of blacks, while all the hundreds 

 of ants over the large area of five or six square meeters had been 

 completely drained off, like water out of a dish, into this new 

 course. After a moment of creeping march ( not a true halt, Fig. 

 1, d.), in which the advance apparently gave time for reinforce- 



