are swept off their feet and, without loosing hold of their prizes,
drift away, land on some shoal, regain the bank and renew their search
for a ford. A few straws borne on the waters stop and become so many
shaky bridges on which the Ants climb. Dry olive-leaves are converted
into rafts, each with its load of passengers. The more venturesome,
partly by their own efforts, partly by good luck, reach the opposite
bank without adventitious aid. I see some who, dragged by the current
to one or the other bank, two or three yards off, seem very much
concerned as to what they shall do next. Amid this disorder, amid the
dangers of drowning, not one lets go her booty. She would not dream of
doing so: death sooner than that! In a word, the torrent is crossed
somehow or other along the regular track.

The scent of the road cannot be the cause of this, it seems to me, for
the torrent not only washed the ground some time beforehand but also
pours fresh water on it all the time that the crossing is taking
place. Let us now see what will happen when the formic scent, if there
really be one on the trail, is replaced by another, much stronger
odour, one perceptible to our own sense of smell, which the first is
not, at least not under present conditions.

I wait for a third sortie and, at one point in the road taken by the
Ants, rub the ground with some handfuls of freshly gathered mint. I
cover the track, a little farther on, with the leaves of the same
plant. The Ants, on their return, cross the section over which the
mint was rubbed without apparently giving it a thought; they hesitate
in front of the section heaped up with leaves and then go straight on.

After these two experiments, first with the torrent of water which
washes away all traces of smell from the ground and then with the mint