260 KANSAS UNIVERSITY SCIENCE' BULLETIN. 



Sharp suggests regarding Eumenes, to saliva or some other 

 buccal secretion which the wasp may mix with the earth and 

 water during the construction of the tube. 



One purpose of this tube, as has been suggested by Messrs. 

 Hungerford and Williams regarding the tube of 0. mmultatus, 

 is to hinder parasites from finding the entrance to the burrow. 

 I shall discuss this in my notes on parasites. 



The very beginning of nest-building — that is, the location of 

 the site — I observed but once, in Ness county. Here a wasp 

 was walking rapidly back and forth on the face of the cliff, 

 covering an area of a few square inches. Occasionally she 

 would stop and test the surface with her mandibles. After 

 two or three minutes of this surveying she took wing and zig- 

 zagged up and down a few inches in front of the area over 

 which she had been running. She alighted, then repeated the 

 uncertain flight in front of the cliff, and again alighted in the 

 same place. Again she took wing, this time making a few 

 large zigzag circles before the face of the cliff, and then flying 

 away. 



I had watched her performance with curiosity, but did not 

 realize its importance until she had returned a minute later 

 with water. She flew almost directly to the place she had so 

 carefully surveyed, wet a spot, and began digging. 



0. papagorum dug rapidly both with her mandibles and her 

 fore feet, pulling the moist earth to the edge of the burrow, 

 and there pressing it against the bank, making a thick founda- 

 tion for the tube wall. While her head and fore legs were 

 constantly at work within the burrow, the rest of her body 

 also was in motion, swinging around the burrow entrance. 

 At one instant the wasp was facing the lower side of the bur- 

 row ; the next instant she might have changed her position so 

 as to be facing the opposite way. The burrow was an axis 

 about which the wasp's body swung back and forth. 



Soon the tube became so long that it was impossible to pull 

 the earth to its edge without backing out. Then Mrs. Wasp 

 began to form the excavated earth into pellets, which she car- 

 ried out in her mandibles to add to the length of the tube. 

 She would then press the tip of her abdomen against the out- 

 side of the tube while she worked with her fore feet and 

 mandibles within. 



After she had been digging for three and one-half minutes 

 she went for more water. This trip occupied forty seconds. 



