Water-carriers may be distinguished from nectar-carriers by gently pressing on the abdomen of the loaded bee while it is held fast on a sheet of filter paper. If the disgorged honey-sac contents is nectar, a translucent spot will be produced on the filter paper; whereas, if it is only water, no such spot will remain upon drying. No suitable chemical test was found. Individuals selected by means of this test showed that nectar-carriers working on white sweet clover required on the average, one-half to three-quarters of an hour to make a round trip, while water-carriers, obtaining their loads within 50 yards of the apiary, completed their round trips in 5 minutes on the average.