The bee visits the flower for pollen; contrary, however, to the statement of Professor Todd, that “the flowers have neither nectar nor odor,” the writers observed that, especially in the early morning, the odor was decidedly pronounced. It was observed that the bee collected no pollen from the large stamen, but took it regularly from the four smaller. This it did by grasping the anthers, one at a time, near the base, and forcing the pollen out through the terminal pores, by pinching it throughout the length between its mandibles. An exception to this in the case of Agapostemon texanus Cress, is already noted in the list of species. It will be remarked that our observations on this point correspond in general to those of Professor Todd.
Of course the statement of Professor Todd, that the next flower of the opposite type which is visited by the bee is very apt to be on another plant, loses entirely its significance, since it has been shown that the flowers on a branch are not at all likely to be all right- or left-handed. In visiting the flowers, the humblebees, as a general rule, simply pass to the flower most conveniently at hand, and this flower is very apt to be on the same plant, especially where the plants are at all large. The humblebees especially work vigorously in the early morning. In a patch of S. rostratum examined between eight and nine o’clock, in St. Joseph, Mo., nearly all the flowers had already been visited. At this time fifteen specimens of humblebees were taken. A great many flowers would be visited by the bee before it found one which had not already been despoiled of its pollen. In visiting such flowers, the bee would alight for a moment on the pistil and large stamens, as described above, and then pass on to the next flower when it had ascertained that there was no pollen present. In this way over twenty flowers may be visited in a minute. It will be seen that, when the bees are at all numerous and as well dusted with pollen as they usually are, the pistil is almost certain to receive pollen, and fertilization to be effected, especially if the pollen from the small stamens is functional.
Among other insects found visiting the plant, the honey-bee was most frequent.
As will be noticed from our list, some insects visit the plants without effecting cross-pollination. Those insects which obtain pollen in an illegitimate manner do not secure it from the small stamens exclusively, but almost invariably visit the large stamen as well.
The adaptation of the plant to propagation by the production of seeds is of considerable significance.[Q]
A normal plant will produce in the neighborhood of 7000 seeds. In making observations on this point, it was found from five pods examined there was an average of fifty-six seeds.
| Pod | 1 | contained | 66 | seeds. |
| " | 2 | " | 53 | " |
| " | 3 | " | 51 | " |
| " | 4 | " | 53 | " |
| " | 5 | " | 58 | " |
| 281 | seeds; av., 56. | |||
Pods 4 and 5 were from the same plant but separate racemes; the others were from different plants. In determining the average number of seeds produced by the plant, five plants growing normally and in different localities were observed, with the following results:
| Plant | 1 | 192 | pods. |
| " | 2 | 50 | " |
| " | 3 | 66 | " |
| " | 4 | 113 | " |
| " | 5 | 210 | " |
Taking the average of fifty-six seeds per pod obtained above, we see that the plant producing 122.5 pods, the average from the preceding table, would produce about 7000 seeds.