1. The honeybee changes the concentration of nectar or sirup only very slightly while en route to the hive.

2. The change is a decrease instead of an increase as has been assumed by many heretofore.

3. The amount of decrease varies directly with the concentration of the nectar or sirup.

4. Observed mean decreases varied from one-fiftieth of 1 percent on a 13 percent sirup to 1.8 percent on a 64 percent sirup.

5. The average decrease for Iowa nectars commonly gathered by the honeybee is about 1 percent.

6. "Carry-over" from the previous load is relatively unimportant, as a rule, and may be disregarded when using an average based upon determinations from 10 or more honey-sacs.

7. Changes in concentration of nectar or sirup while in the honey-sac are independent of the factor of flight or the absence thereof.

8. For most practical purposes, it may be considered that the honeybee does not appreciably change the concentration of nectar while gathering a load of it and carrying it to the hive.

9. Should it be desired to make correction for the slight change introduced by the honeybee, this may be done readily by using the regression equation given on page 232.

10. Honey-sac contents of honeybees captured while gathering nectar from a given plant species give a close approximation to the actual concentration of the nectar as found in those flowers.

11. Highly trustworthy averages were obtained from lots comprising 10 honey-sacs, determined individually.

12. The determination of nectar concentration through the use of honey-sac contents opens greatly enlarged possibilities for gaining new knowledge concerning sugar concentrations in the nectars of plants.