350 WASP STUDIES AFIELD 



sealing up the hole; the aperture was already closed and 

 she was occupied with biting out mud alongside the burrow 

 and adding it to the plug. Suddenly she flew away and 

 returned in five minutes without mud but with water, and 

 moistened the earth beside the plug. We eagerly pressed 

 too close, to study her method, and she fled. Three minutes 

 later she returned, bringing a pellet of mud from afar, and 

 applied it, went out and got another ball in the same way 

 and added that; then, with the surplus water in her mouth, 

 she soaked up more earth beside the hole, dug it out and 

 plastered it also over the closure. Here both methods were 

 used : bringing in water and making mud near at hand, and 

 carrying mud from afar. In applying this mud, she re- 

 volved about the hole, taking every position describing a 

 circle. After two minutes, she brought in still another ball 

 of mud. For a few moments our attention was drawn to 

 another little wasp nearby, and when we turned back, the 

 first had torn out all her carefully constructed masonry, 

 opened her seal and was busy inside the burrow. What 

 she was doing there we could not ascertain, but when we 

 returned to the scene at 4 p. m. the burrow was once more 

 nicely sealed. A large, freshly-made depression beside the 

 hole gave evidence that much of the material for the plug 

 had been gathered right on the premises. Upon opening 

 this nest, we found it had first an air-space of one-half 

 inch depth, then a partition and, a little way behind this, 

 the remains of another partition the one evidently broken 

 into when she demolished the front door. Through poor 

 manipulation in opening the nest, we got the contents of 

 two cells together, which comprised thirty-six caterpillars 

 of the kind already mentioned, and an egg for each com- 

 partment. Almost all of the caterpillars spontaneously ex- 

 hibited signs of life. The eggs were not carelessly tucked 

 in among the writhing caterpillars, but in true Eumenid 



