At another time, we saw a biguttatus trying to run backward with a little bit of a spider, which she had lifted from the ground and was carrying in her mandibles,—trying to run backward, because it is the rule with this genus to move in that way when encumbered with a load, it being easier to drag a heavy spider than to pick it up and go forward. The wasp in question was drawn in two directions. Instinct made her go backward, although in this particular case it was needless, while she felt a constant desire to turn and go straight ahead. As a result she waltzed slowly over the sand in a series of overlapping circles, her head turned toward every point of the compass in succession, a kind of progress most amusing to the lookers–on. Biguttatus is not strong enough to fly when laden, but it is the habit of the species to climb backwards to the top of every obstacle in the path, and from this vantage point to gain time by taking a downward flight in the direction of the nest. It is only in the case of tall, smooth–stemmed plants and grasses that the advantage gained is enough to repay the trouble of climbing, and we have often thought that the notion costs the wasp more trouble than it is worth,—as was certainly the case with one comical little creature that carried the idea to the extreme of folly. Not only did she scale objects in her way, but just as old Dr. Johnson felt that he had to touch every tree and post as he walked along, so when this wasp saw, out of the corner of her eye, a stone or a plant three or four inches to one side, it called upon her to climb, and climb she did, although she was obliged to leave her proper path to do it. It is obviously more difficult to distinguish actions of intelligence than of instinct. One must be familiar with the normal conditions of the insects in question before he is able to note those slight changes in the environment that offer some opportunity for an adaptation of means to ends, or before he is competent to devise experiments which will test their powers in this direction.