POWERS OF COMMUNICATION. 167 
the larve ; but only one passed over the little bridge to 
the larve, while 15 went over the bridge L tol On 
repeating this experiment with another marked 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 larve, 8 went over L to 1, 
and the remainder on to D. 
In another similar experiment the marked ant made 
16 journeys; and during the same time 13 other ants 
vame to the point of junction. Of these 13, 6 went 
on to D, 7 crossed over L to I, and not one found the 
larve. Thus altogether, out of 92 ants, 30 went on to 
p, 51 crossed over in the wrong direction to 1, and only 
11 found their way to the larve. 
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 1, and only Fig. 4. 
10 to the larve. 
This, I think, gives strong reason to 
A 
conclude that, under such circumstances. 
ants track one another by scent. 
I then slightly altered the arrange- B 
ment of the papers as shown in the 
accompanying diagram (fig. 4). A, as 
before, is the nest, o being the door. 
B is the board; A is a glass on which 
are placed the larve; m is a similar glass, but empty 5 
n a strip of paper: to the end of ~ are pinned two 
