48 THE S OLITA RY WA SPS. 



if they had worked only at their former rate. ^Neither the 

 coolness of the air nor the darkness of the night had made the 

 slig-htest difference to them. After watching them a few min- 

 utes and marvelling at their powers of endurance, we cleared 

 out the tubes and returaed to bed. At half past eight we found 

 them still at work. Unlike us, they had taken no morning nap, 

 but had gone on with their tunneling in their usual steady way. 



From this time their ways diverged and they must be de- 

 scribed separately. At nine o'clock the one that we had first 

 seen came up to the opening walking head first, and flew off, re- 

 maining away seven minutes. When she returned she at once 

 resumed her work and kept at it without a pause until two in 

 the afternoon. At this hour she went away and we never saw 

 her again. We suppose that she was killed, for it seems im- 

 probable that so faitliful a creature could have deserted her 

 half-finished home. Pompilus quinquenotafus often deserted a 

 partly finished nest for some more enticing spot, and Spliex 

 started several excavations before making a final choice, but we 

 cannot believe that there was anything fickle about Crahro. 



The second wasp came up head first to the entrance of her 

 hole at two minutes after nine, as though she had been influ- 

 enced, in some subtle way, by her neighbor's example, but after 

 looking about for a moment she went back. She repeated this 

 observation several times and finally, at twenty-five minutes 

 after nine, came out and flew to a leaf near by. Then she cir- 

 cled around, alighting a number of times, and, at last, departed. 

 Her stay was brief for at just thirty-five minutes after nine she 

 returned and at once settled down to her work. 



We now began to make notes as to the length of time that it 

 took her to go down and bring back her load. We timed her 

 again ana again and found that she was remarkably regular, 

 each of her trips occupying from forty-five to fifty seconds. 



All that day we kept her under strict surveillance and never 

 once did she suspend her operations either for rest or refrech- 

 ment. Late in the afternoon while we sat watching her as she 

 appeared and disappeared with almost the regularity of clock 



