274 CLARENCE P. CUSTER AND CHARLES H. HICKS. 



1 146. Arrives at nest 2. Leaves after two seconds and again 

 feeds. 



1:48. Arrives at nest 2. Walks all over colony looking into 

 several nests and returns to this one. 



i : 49. Flies away. 



1:51. Arrives with resin at nest 2. 



1:51^. Obtains piece of chaff and takes to nest i. Gets 

 stick midway between nests i and 2 and carries it to nest 2. 



2:01. Leaves nest 2 and obtains resin after feeding on flowers 

 of Grindelia, etc. (c). 



The entrance to the tunnel, after the completion of the cells, 

 is closed by a plug of resin, chaff and other materials. From 

 several plugs taken out, we find that the resinous part is about 

 2 mm. thick. Usually, in constructing the plug, the bee first 

 places a few pieces of chaff, sticks, etc., in the entrance and then 

 builds a resin cap over the projecting ends. Beyond the plug, 

 towards the cells, the tunnel is often empty and may be coated 

 with resin. 



One of us (Hicks) (5) has described the cells of D. sayi. Last 

 summer it was not known whether all the materials found in the 

 resin had been carried there by the bee or were there by chance. 

 Observations this summer show that she obtains the chaff, sticks, 

 etc., which are found mixed with this resin, from the vicinity of 

 the nest. In some instances she has been found to carry fifty or 

 more pieces of chaff, etc., into one tunnel until it was filled. 

 After this she finished the nest with a resin plug. The resin cells 

 are often found attached to the grass roots in similar fashion to 

 peanuts on the stem. 



D. sayi varies considerably in the distance which she carries 

 the stones, dried mud, etc., with which she constructs the nest. 

 Bee J (attending to nest 9) is seen to make many trips with plates 

 of dried mud from an old mud puddle, six yards away, to her nest. 

 Bee E (attending to nests 5 and 14) is seen to carry many large 

 pebbles to her nest from a sand pile eleven yards away. She 

 places these in nest 14 after having plugged up 5 (c). 



D. sayi may also obtain chaff and sticks from a distance varying 

 from three inches to three yards away. One individual selected 

 material near the nest but did not repeatedly obtain it from the 



