red-clover flowers, while other investigators say that honeybees collect pollen from red-clover flowers and thereby cross-pollinate them.
In order to determine the efficiency of the honeybee as a cross-pollinator of red-clover, a cage 12 feet square and 6 feet high, made of galvanized-wire screen having 4 meshes to the linear inch, was erected in the same field as the bumblebee cage. It was previously determined that a mesh of this size would permit a honeybee, or any insect smaller than a honeybee, to pass through, but would not permit bumblebees to do so. Two weeks before the clover came into bloom a small colony of honeybees was placed in one corner of this cage. The bees soon learned to pass through the screen. By the time the clover began to bloom the bees had become accustomed to the cage, and while most of them worked on the flowers outside, some could always be seen at work on the clover within the cage. Bees working on the clover within the cage were observed to collect pollen from the flowers and carry it to the hive.
As soon as all the flowers in the cage were mature, an area 4 feet square was measured off and all heads within this area were collected, kept separate, and thrashed out by hand. Of the 623 heads collected from this area an average of 37.2 seeds per head was obtained. This is 6.8 seeds more per head than in the case of the red-clover flowers that were cross-pollinated by bumblebees.
The higher yield of seed obtained in the honeybee cage than in the bumblebee cage may be attributed, at least in part, to the larger number of bees which had access to this clover.
uring the period that these experiments were carried on the normal rainfall was somewhat below normal. Also while the red-clover was in bloom very few other nectar-producing plants were to be found. From the experiments carried on it has, however, been proved that the honeybee