THE SAND-LOVING AMMOPHILA 231 



in the neck of the vial ; she promptly repeated the perform- 

 ance. Next we placed it at the middle of the vial; again she 

 returned at once, hesitated but finally went in and took her 

 booty homeward. At last we placed the caterpillar in the 

 extreme end of the vial ; she certainly appeared to be learning 

 by this time, for she returned promptly, entered unflinch- 

 ingly and dragged her property out. Once more we tried 

 her, but it is little wonder that, after so much annoyance, she 

 flew away in disgust. The reader may give whatever in- 

 terpretation he chooses to this experiment, but one who saw 

 the wasp would say that she was a very apt learner in the 

 school of experience. 



It is difficult indeed to refrain from using the term 

 "practical judgment" in the discussion of some of Ammo- 

 phila's ways. It is truly marvellous to see her choosing, 

 with such care and nicety, a little clod with which tempor- 

 arily to cover her hole while she goes away in quest of prey. 

 She passes by one after another, pausing a moment to look 

 at or sometimes to turn over one which may be a trifle too 

 large or too small, but finally selecting one, perhaps from 

 among a dozen or forty others, which is just right to serve 

 as a lid. If, after adjusting this lid, the nest is still notice- 

 able on the landscape, she sometimes scratches one or two 

 throws of loose dirt or dust around it to render it less con- 

 spicuous. We have only twice seen an Amnwphila use any- 

 thing which was small enough to fall into the hole. One 

 of these was a wasp which abandoned her burrow when it 

 was half -dug, and, for some unknown reason, scratched sev- 

 eral tiny clods and leaf-fragments into it before leaving. 

 The other case was that of a wasp which certainly appeared 

 to be actually experimenting, and learning eventually by 

 her experience. Her conduct was so interesting that per- 

 haps the details of it will not be out of place here. We 

 found her running to and fro over the bare ground of the 



