A WEEK WITH A MINING EUMENID. 157 



It usually takes a little over an hour to reach this point in the 

 digging of the burrow. In removing the dirt she goes in head 

 first and comes out backwards. 



Isely thinks that this species carries the water in her jaws. He 

 says ('14, p. 286) : " Mrs. Wasp flew in the direction of the river 

 and returned with her mouth parts glistening." Although I 

 watched the wasps carefully, I failed to detect water glistening on 

 their mouth parts. However, I know that they carry water to 

 moisten the clay; because, immediately after a wasp that has re- 

 turned from the streamlet applies her head to the ground, the clay 

 glistens for a moment and then becomes dull. The water sparkles 

 until it is absorbed by the clay. Hence I am inclined to believe, 

 with the Raus ('18, p. 314), that the water is carried in some part 

 of the digestive tract (probably the crop). 



In a previous paragraph I have stated that each pellet, as it is 

 removed, is carried to a distance of from two to twenty-four inches 

 and deposited. How carried? According to Isely ('14, p. 285), 

 she flies and drops them all, in about the same place, at approxi- 

 mately eighteen inches from the nest. The Raus ('18, p. 314) 

 write : " She would then back out of her hole with a round, well- 

 formed pellet of mud in her mandible, always fly from two to 

 fifteen inches and drop it." They do not state whether the pellets 

 are scattered around or deposited in one place, but the illustration 

 furnished pictures them distributed, in a single layer, over the 

 ground. Of the colonies I am describing, in one (Fig. i, B, a) 

 the pellets were scattered, in a single layer, over the plot ; in the 

 other two, in addition to the scattered pellets, there were piles of 

 them near certain nests. Some wasps were flying and dropping 

 the pellets, some were walking from the nest and depositing the 

 pellets and then flying back to the nest, some were walking from 

 the nest, depositing the pellets, and then walking back to it. It 



FIG. i. Views of the habitat of the colonies studied. A. Near view of 

 the colony located at a in B. The specks on the ground are pellets dropped 

 by the wasps. B. View of the environment of the three colonies : a, location 

 of a colony situated where the ground is absolutely free from vegetation ; c, 

 location of a colony where a few low-growing weeds partly cover the ground ; 

 e, a colony similar to c. C. A near view of the colony located at c in B. 

 The specks on the ground are pellets dropped by the wasps. 



