ar, and she ceases to climb blades of
grass, etc., now she is in the midst of well-known scenes, and at last
she fairly races into her nest.

In this instance the ant is led at first by her sense of direction
alone; as soon, however, as she comes to country which she has hunted
over, and with which she is familiar, memory comes into play and the
sense of direction ceases to act, or, if it acts at all, it acts
unconsciously.

Sand-wasps build their nests in the ground, and, when leaving their
tunnels in search of food for the prospective grubs, always circle about
them and observe the lay of the land before taking their departure.
Numerous sand-wasps build in the interstices between the bricks of a
pavement in front of my house. When one leaves her tunnel she will fly
about the orifice for several seconds (taking observations) before she
finally flies away. When she returns, she hovers about the orifice, or,
rather, in its neighborhood, until she is quite certain that it is the
entrance to her home, when she will dart in with such rapidity that the
eye can scarcely follow her movements.

On one occasion, I covered the pavement surrounding the entrance with
newspapers, leaving, however, about three inches on all sides of the
orifice uncovered. When the wasp returned she seemed to be completely at
a loss what to do. She hovered about for at least an hour, and then flew
away.

Thinking that this experiment was too great a tax on the wasp's
intelligence, I tried the following, which seemed to me to be nearer a
natural happening than the former experiment. I believe that, in
studying mind in the lower animals, one's experiments should be as near
nature as they can possibly be.

As soon as the wasp had left her tunnel, I covered the surface of the
bricks and the interstices between them, for several feet around the
orifice of the tunnel, with sand. This might have happened, naturally,
through the agency of the wind.

When the wasp returned, it was perfectly apparent that she did not
recognize her domicile. She flew here and there and round about, but she
would not alight. Finally, I swept the sand away, when she at once flew
to her nest and entered.

In my opinion, these experiments prove very clearly the presence of
memory of locality in these insects. The sense of direction, which a
vast majority of the lower animals possess in some degree, is, however,
of material assistance to their memory; this special sense will