1910] Burrill, How Sanguinary Ants Changs Direction. 125 



must conclude that all ants do not tend to straighten out the trail 

 universally and invariably. 



The following two instances of straightening out the line of 

 scent are by two different nests of formica sanguined rubicunda 

 X subintegra in forays directed against Formica fusca subscricea 

 at the homestead, North Brookfield, Mass. The first account, 

 Aug. 23, 1899, is of a nest whose red ants marched about four met- 

 ers (12'), over a lawn east northeast, to a colony purely of blacks 

 ( Fig. 1, o opposite a) which they subdued by 11 a. m. I found the 

 black queen hiding with 60 or so attendant blacks in a grass clump 

 about 1.2 meters northeast of their home, a direction at an oblique 

 angle with the line of foray. As an experiment, I brushed my 

 hand over the grass from the invested nest towards the queen, as 

 a lure to red soldiers to give chase. Hardly a dozen outposts of 

 these warriors responded, the rest being too intent on the cap- 

 tured nest. But I kept on attracting the few, till some four came 

 in touch with hlacks on the outskirts of the clump, and five or six 

 more w T ere straggling along that way. The whole manner of the 

 first four, on meeting the blacks, changed at once, — from the 

 purely aggressive at my disturbance, they became cautious but 

 more excited, and two started back on the double quick, to their 

 comrades at the captured nest. In two minutes from the time 

 these two had reached and mingled among the many at the cap- 

 tured nest, excited jerks — the well-known jerk signal of antennae, 

 somewhat like a small pup making feints at a cat, — began passing 

 among all red ants about the region, most red ants south and east 

 of the captured nest were called in, and many groups of them be- 

 gan hurrying off to this quarter northeast of the nest ; the news 

 passed on in the same manner down the line between nests and 

 quickened the column all the four meters of march between nests 

 within a period of three minutes more. In the meantime, the queen 

 was startled out of hiding and dragged by her antennae by a black 

 attendant, .3 m. further off, while the rest of her body-guard was 

 becoming badly scattered or engaged at the clump by the red ants. 

 Within five minutes more, the reds were swarming all over the 

 clump. 



The most remarkable thing to me was the speed of mobilization 

 of the red ants : within ten minutes from the time the first mes- 

 sengers produced excitement at the captured nest by their return 



