524 PROCEEDINGS OF THE ACADEMY OF [Oct., 



liour were recorded. Dot One made seventy-two journeys, going 

 in and returning by the e-d run. Deviations, apparently caused 

 by pressure or by momentum, were sometimes made on departing 

 from Tor from I, but she never deviated from her trail more than 

 four times her own length without discovering her error and retrac- 

 ing her path into the c-cl run. 



Dot Two made sixty-one round journeys by the c-d run. Other 

 ants were at the same time going in and returning by the same and 

 by other routes. 



Dot Three made forty round trips. The first fourteen were all 

 by the n run. She was then carried, apparently by her own 

 momentum under a heavy burden, into the a run, and there 

 wandered to and fro, utterly lost, notwithstanding the frequent 

 passing of her comrades. She eventually made her way by the a 

 run into /. Somewhat later, under similar momentum, she like- 

 wise floundered through c-d, and then at intervals she afterward, 

 with no hesitation, four times took the e-d route to /. All her 

 other ingoings and all her returns were via the n run. A few 

 hours later, when I again set the ants to work. Dot Three again 

 took the n route, and in an hour made forty-eight round trips 

 thereby. A few times she made impetuous starts into other runs, 

 but she every time retraced her steps and followed her best-known 

 path. I then removed her to a Petri cell, closed the entrances to 

 all runs other than c-d and m, and put several unmarked ants to 

 the work of carrying in pupre. During that afternoon and the 

 succeeding forenoon, these ants made over three hundred round 

 trips through vi and c-d. When these two runs had thus been 

 thoroughly scented by other ants, and while their trails were yet 

 fresh, I unclosed all the runs and put Dot Three in through T. 

 After an absence of nineteen hours, she made ner first trip, with- 

 out a burden, through )i, and then resumed tJje carrying in of 

 pupoe, making fifty-four round journeys in an hour, going in forty- 

 eight times by the n run and six times by the c-d run, and return- 

 ing fifty-two times by the n run and twice by the c-d run. Not 

 once did she enter the m run, which had duriug the previous hour 

 been traversed hundreds of times by her comrades. 



The following day, no use having been made of the maze in the 

 interval, I again put Dot Three in at T. She at once went, with- 

 out a burden, through a, and returned through n. During the 



