POWERS OF COMMUNICATION. 167 



the larvae ; but only one passed over the little bridge to 

 the larvae, while 15 went over the bridge L to I. On 

 repeating this experiment with another maiked ant, she 

 herself made 40 journeys, during which 19 other ants 

 found their way to the point of junction. Only 2 went 

 over the little bridge to the larvae, 8 went over L to i, 

 and the remainder on to d. 



In another similar experiment the marked ant made 

 16 journeys 5 and during the same time 13 other ants 

 came to the point of junction. Of these 13, 6 went 

 on to D, 7 crossed over L to i, and not one found the 

 larvae. Thus altogether, out of 92 ants, 30 went on to 

 D, 51 crossed over in the wrong direction to l, and only 

 1 1 found their way to the larvae. 



From January 2 to January 24 (1875) I made a 

 series of similar observations ; and during this time 56 

 ants came in all. Of these, 20 went straight on to 

 D, 26 across the paper to i, and only 

 10 to the larvse. 



This, I think, gives strong reason to 

 conclude that, under such circumstances, 

 ants track one another by scent. 



I then slightly altered the arrange- 

 ment of the papers as shown in the 

 accompanying diagram (fig. 4). A, as M, 



before, is the nest, o being the door. i/ Vv 



B is the board ; A is a glass on which 



are placed the larvae ; m is a similar glass, but empty | 



n a strip of paper : to the end of n are ginned t«ro 



