Page:Popular Science Monthly Volume 5.djvu/145

Rh forgotten in the next. Thirty years ago Charles Darwin discovered the German's idea in an old, castaway volume, and at once he began to employ his matchless powers of observation in questioning Nature for its truth. He has taught us how to use our eyes. Let us look.

One of our most beautiful shrubs is the mountain-laurel (Kalmia latifolia). It blossoms all over in corymbs of bell-shaped flowers, white, tinged with red, having short nectaries and recurved stamens, whose anthers are inserted in little pits of the corolla. In Fig. 1 the flower is shown with the anthers out of their sockets. In Fig. 2 we have a section of the flower showing the recurved stamens and the anthers resting in their pouches. It will be seen that the stamens are shorter than the style. How is the anther to be liberated from the pouch? And how is the pollen to be carried to the stigma?



The kalmia is one of the most showy shrubs along the wooded way-sides of New England, and is very attractive to bumble-bees. Now, your bumble-bee is the clumsiest of insect. His action is as ungraceful as his person. He can do nothing expertly and neatly. He cannot even sting you while on the wing, but must first alight and adjust himself. At nectar-getting he is as clumsy as at stinging. He sprawls over a flower, pushes here and there among the delicate organs, and gets himself thoroughly bedaubed with pollen. This clumsiness makes him a good marriage-priest for the flowers. The color of the laurel attracts him, and the nectary promises honey. He lights, gets his legs entangled among the stamens, and as he jostles them they spring from their little pits with a sharp snap and scatter their pollen over his back. In visiting another flower some of the pollen will find its way to the stigma and thus secure cross-fertilization.

The iris would seem, at first thought, to have been specially planned for self-fertilization. As will be seen in Fig. 3, the petaloid stigma covers the petaloid stamen. But a most curious fact is that, while the stigmatic surface is brought right up against the stamen, the