128 Bulletin Wisconsin Natural History Society. [Vol. 8, Xo. 3. 



ments to gather until the advance became a thick pack a foot and a 

 half wide," the soldiers 'with a cheer of antennae touches, plunged 

 like a drove of hounds, straight at and down the holes. Blacks 

 swarmed out only to fall in death grapples with eager soldiers in 

 their overwhelming rush. By this time the line of march all the 

 wav back to the home nest was quickening its pace." 3 In three 

 minutes appeared the first soldier with a pupa trophy, and within 

 six minutes from the attack, a stream of burdened soldiers was 

 on the way home. Ten minutes later; 140 burdened soldiers 

 passed a given point in five minutes, fifteen minutes later another 

 5-minute count gave 180 burdened red ants homeward bound 

 and similar counts could have been repeated until nearly 7 p.m. 

 But to omit my further notes with details about apparent mobiliz- 

 ing officers, messengers, etc., as soon as the new advance began, 

 the right-angled turn was cut off more and more into a sweeping 

 curve, which the booty-laden reds followed in preference to the 

 right-angled turn by which they had come. This is in harmony 

 with Lubbock's conclusion 4 about a different kind of test, an arti- 

 ficial one, and may explain also the confusion of reds at the end 

 of my next example. Lubbock says of his test, "They knew they 

 were being sent a long way round, and were attempting to make a 

 shorter cut." 



In contrast with the above two examples is this one of choosing 

 a roundabout route for its ease ( ?). Aug. 16, 1900, the nest last 

 mentioned of Formica sanguined rubicunda X siibintegra sent out 

 just before 2 p. m. a squad of fifteen to twenty reds. It was after 

 a previous day and a half of rain, including the morning of the 

 above date, and the wet lawn was drying off fast. This squad of 

 reds crossed the sunlit lawn and driveway, up the grass banking, 

 across a narrow strip of tar walk, into thicker grass still dripping 



3) There is a chance for error here in judging- varying speeds of ants, 

 for, after an observer has been bending over on hands and knees to watch at- 

 tentively, and then jumps up to watch another part of the trail, the too fre- 

 quent changes in the blood circulation is sufficient to make one's eyes swim 

 and it may have other psychological disconcertments that only a trained 

 psychologist would appreciate. Ants do not wait, however, for observers to 

 become normal, so the seeming changes in speed are given for what they are 

 worth. These changes in speed have been noted under many other conditions 

 of observation, — changes, especially in the cases cited in this paper, when the 

 ants were under intense excitement. It should be perfectly feasible for some 

 one to test the speed of foraying ants at diffrent points, or better, at the same 

 point at different times, preferably on some foot or two of a smooth part of 

 the trail, where their speed could naturally keep uniform, and thus show the 

 results of communication or excitement from fresh scent in terms of speed. 



4) lb. p. 271. 



