78 MY STUDIO NEIGHBORS 



off to its long sand tunnels by short flights from 

 successive elevated points, such as the limbs of 

 trees and summits of rocks, to w^hich it repeatedly 

 lugs its clumsy prey. In the present instance the 

 contrast between the slight body of the wasp and 

 the plump dimensions of the caterpillar was even 

 more marked, and I determined to ascertain the 

 proportionate weight of victor and victim. Con- 

 structing a tiny pair of balances with a dead grass 

 stalk, thread, and two disks of paper, I weighed 

 the wasp, using small square pieces of paper of 

 equal size as my weights. I found that the wasp 

 exactly balanced four of the pieces. Removing 

 the wasp and substituting the caterpillar, I pro- 

 ceeded to add piece after piece of the paper 

 squares until I had reached a total of twenty- 

 eight, or seven times the number required by the 

 wasp, before the scales balanced. Similar experi- 

 ments with the tiny black wasp and its spider vic- 

 tim showed precisely the same proportion, and 

 the ratio was once increased eight to one in the 

 instance of another species of slender orange-and- 

 black -bodied digger which I subsequently found 

 tugging its caterpillar prey upon my door -step 

 patch. 



The peculiar feature of the piling of stones above 

 the completed burrow was not a mere individual ag- 



