1912] Turner — Sphex Overcoming Obstacles 101 



then descended to the ground, deposited her spider in the grass, 

 made a short flight of orientation and then revisited the cellar 

 door. 



Returning to the school yard, the wasp picked up the spider and 

 began to drag it up the fence. Soon she backed into the upper 

 scantling and found it impossible to climb over it with her burden. 

 This time, however, she did not return to the ground; but, chang- 

 ing her tactics, Sphex backed away towards the south until she 

 reached the corner of the fence, which was fully six feet away. 

 Then backing towards the east, she moved along the front fence 

 until she had arrived at the space between two pickets. Still 

 dragging the spider after her, the wasp backed through to the out- 

 side of the fence. Turning around the wasp moved westward 

 and downward until she reached the ground at the southwest cor- 

 ner of the fence, where she deposited her spider in a clump of grass. 

 After making a short flight of orientation, the wasp flew, in prac- 

 tically a straight line, to the cellar door. The line of flight on 

 this occasion made an angle of about 45 degrees with the line of 

 her former flights to the door. 



Soon Sphex returned to the fence corner, seized the spider by 

 its pedipalpus and, walking backwards, dragged the spider across 

 the ground to the cellar door. There she deposited the spider on 

 the ground and, after a short flight of orientation, flew to and ex- 

 amined the door. Returning to the spider, the wasp attempted 

 to drag it to a crack at the top of the cellar door. The task seemed 

 to be too difflcult, and, after several failures, the wasp placed the 

 spider on the ground, and, without making a flight of orienta- 

 tion reexamined the cellar door. Returning to the spider, she 

 attempted to drag it to an opening that was much nearer the 

 ground ; but was defeated by a scantling over which she could not 

 drag her burden. Depositing the spider on the ground, she flew 

 to the door and soon found another opening. When she attempted 

 to drag the spider to this opening, she was prevented by another 

 piece of scantling. Once more the spider was returned to the 

 ground while the wasp made another careful examination of the 

 cellar door. Returning to the spider, Sphex picked it up and, 

 moving backwards, dragged it to a knot hole in the door and passed 

 into the cellar with her prey. 



The behavior of this wasp does not harmonize at all with the 



