Part I.--Pollination Studies of Seed Production.

Unsatisfactory yields of sweet-clover seed 1 Previous investigations of the pollination of sweet clover 2 Outline of pollinating experiments 3 Structure of the flowers of Melilotus alba 4 Development of the floral organs of sweet clover 5 Fertilization in Melilotus alba 8 Development of the seed 8 Mature pollen of sweet clover 9 Germination of the pollen 9 Cross-pollination and self-pollination of sweet clover 10 Artificial manipulation of sweet-clover flowers 10 Seed production of Melilotus alba under ordinary field conditions 13 Efficiency of certain kinds of insects as pollinators of sweet clover 14 Relation of the position of the flowers on Melilotus alba plants to seed production 19 Influence of the weather at blossoming time upon seed production 20 Insect pollinators of sweet clover 21 Effect of moisture upon the production of Melilotus alba seed 22