Again we availed ourselves of our opportunity, and substituted our spider for hers. This time it had grown weary of playing its motionless rôle, and frequent readjustments were necessary in order to keep it in position. At the moment that the wasp came back to take it, the spider scrambled from its place and began to make its way along the stem. The wasp evidently saw it, for she hovered over it a moment. She then flew to the next plant, where she hunted about over the leaves and branches in search of her lost treasure. After a time she returned. The spider had now come to a standstill, and the wasp examined it attentively, although without touching it. She then flew away without circling at all, which might, perhaps, be taken as an indication that she had no intention of returning to a place where she had fared so badly. Just at this moment we chanced to see another paralyzed strix hanging near by. Again the exchange of our specimen was accomplished; but when the second wasp came to find her spider she gave us no more satisfaction than the first. The substitute hung there quietly enough. We ourselves could not have distinguished it from the original, but quinquenotatus took a good look at it, decided that something was wrong, hunted about a little for her own spider, and then flew away. We had then, as the fruit of our morning’s work, gained nothing in regard to a knowledge of the stinging habits of our wasp, but at least we had secured three freshly paralyzed spiders to add to our laboratory collection. As to the strix that had so kindly assisted us in our experiments, we placed it on a bush in the pleasantest and most secluded corner of the garden and left it there, wishing it a long and happy life. Later on in the season we tried the same experiment. Taking her spider from quinquenotatus as she was dragging it to her nest, we offered her a very lively strix in its place. She would not notice it at all, and soon flew away. Half an hour later she reappeared, and seemed to be looking for a place to dig. As she ran about on the ground we offered her another spider, dropping it on the ground in front of her. This one behaved admirably, drawing up its legs and keeping perfectly still, not moving even when she felt of it and turned it over, but it was left without any display of interest or emotion.