THE SAND-LOVING AMMOPHILA 221 



for the hunting-grounds. The hole was finished, and she 

 had brought three pieces of dirt and carefully covered it. 

 She flew to a leaf a few inches away. From this perch 

 she descended three times to do some unnecessary scratching 

 over the hole. By these maneuvers she may have been get- 

 ting her landmarks (see fig. 48) in fact, we suspect that 

 she was, for she walked all over this small Solanum (S in 

 the figure) which overhung her burrow (N), examining it 

 all the while, and as she came to the leaf directly above her 

 nest she usually peered down and sometimes descended to do 

 some scratching, then returned to continue her examination 

 of the weed. Then she turned her attention to a small tuft 

 of grass (G), the object next in nearness to her nest, and 

 scrutinized it. After this minute examination, she dropped 

 down upon the earth and walked in an almost perfect circle 

 around the nest, not all at once, but in arcs, and at the ter- 

 mination of each arc she would waltz about in tiny circles, 

 sometimes one whirl, and sometimes two or even three times 

 around, and then proceed with the next arc, without once 

 becoming confused in her directions or missing the lines of 

 her well-defined circle. The little waltzing whirls were al- 

 most always from left to right, but once she circled from 

 right to left. The accompanying crude diagram (fig. 48) 

 will aid in making clear this remarkable performance. While 

 we had no measure of the length of the arcs, it seemed to 

 us they were wonderfully uniform in size. This precision 

 is only in harmony with the other instances of fine physical 

 judgment which we so often see in the conduct of this wasp. 

 At the conclusion of the first circle, she commenced a second 

 of increasing radius, but as she progressed she got to run- 

 ning and hopping, and soon flew away to the vegetation 

 beyond. A moment later we saw her climbing up a rag- 

 weed in the role of a forager. 



She left at 10 o'clock and we could not wait for her return, 



