The Ants Highway. 15 
bearings, but followed each other unhesitatingly in 
the groove. 
When street-pavements are torn up, the human 
stream disperses and flows out on either side till it 
discovers by experience the most convenient make- 
shift passage. What would be the result if this 
Watling-street of the ants were interrupted? Witha 
fragment of wood I rubbed out three inches of the 
path worn in the shallow film of soil deposited over 
the old gravel, smoothing that much down level. 
Instantly the crowd came toa stop. The foremost 
ant halted at the edge where the groove now termi- 
nated, turned round, and had an excited conversation 
with the next by means of their antennz; a third 
came up, a fourth and fifth—a crowd collected, in 
fact. Now, there was no real obstruction—nothing 
to prevent them from rushing across to the spot 
where the path recommenced. Why, then, did they 
pause? Why, presently, begin to explore, right and 
left, darting to one side and then to the other examin- 
ing? Was it not because an old and acquired habit 
was suddenly uprooted? Surely infallible instinct 
could have carried them across the space of three 
inches without any trouble of investigation ? 
In a few seconds one of the exploring parties, 
making a curve, hit the other end of the path, and 
the news was quickly spread, for the rest followed 
almost immediately. Placing a small pebble across 
the track on another occasion caused almost the same 
