POWERS OF COMMUNICATION. 169 
friction of my finger ; on the other hand, the bridge (d) 
had retained the scent, but was so placed as to lead 
away from the larve ; and it will be seen that, under 
these circumstances, out of 41 ants which found their 
way towards the larve as far as e, 14 only passed over 
the bridge f to the larve, while 27 went over the 
bridge d to the empty glass m. 
Taking these observations as a whole, 150 ants 
came to the point ¢, of which 21 only went on to the 
larve, while 95 went away to the empty glass. These 
experiments, therefore, seem to show that when an 
ant has discovered a store of food and others flock to 
it, they are guided in some cases by sight, while in 
others they track one another by scent. 
I then varied the experiment as follows :—I put an 
ant (L. niger) to some larve as usual, and when she knew 
her way, I allowed her to go home on her own legs ; but 
as soon as she emerged from the nest, if she had any 
friends with her, J took her up on a bit of paper and 
carried her to the larvae. Under these circumstances very 
few ants indeed found their way tothem. Thus, on June 
23, 1876, at 5.30, an ant which had been previously 
under observation was put to some larve. She took 
one and returned as usual to the nest. At 5.34 she 
came out with no less than 10 friends, and was then 
transferred to the larva. The others wandered about a 
little, but by degrees returned to the nest, not one of 
them finding their way to the larve. The first ant 
picked up a larva, returned, and again came out 
9 
