Page:Popular Science Monthly Volume 45.djvu/35

 bird, though the smaller of our species, the one I find visiting the arbutus, is more suggestive of a bumblebee. They have long tongues, curled up when not in use, through which they suck the nectar of flowers. Unlike most moths, which fly at dusk or after dark, the sesias are abroad in the bright sunlight.

Occasionally one of the early spring butterflies, especially the American tortoise-shell and the mourning cloak, may be seen hovering over the blossoms.

The insect visitors so far considered are all useful to the mayflower. They fly rapidly from head to head and plant to plant, carrying the pollen which sticks to them from the anthers of the staminate blossoms to the stigmas of the pistillate ones, thus causing the fertilization of the embryos and the development of seeds. But the surface of the rocky hillsides where Epigæa is most thoroughly at home swarms with ants of various species—wingless creatures that dearly love the nectar of flowers. These insects wander everywhere in search of food, and are often seen trying to get at the honey at the bottom of the mayflower corollas. Could they succeed, little would be left for other visitors, and consequently the ants would not only be of practically no value as pollen-carriers—for rarely would one chance to wander from a staminate to a pistillate blossom—but they would also prevent the visits of the useful bees and flies. The plant, however, has fenced out these and other similar unbidden guests by an elaborate chevaux-de-frise, composed of hairs projecting slightly upward from the inner surface of the corolla and the outer surface of the ovary and style. It is easy for a bee, moth, or fly to push its slender tongue down through these hairs to the base of the corolla, but an ant finds it very difficult to force its body down till its mouth is at the bottom.

silk spider of Madagascar spins golden-colored threads, strong enough, according to M. Maindron, to bold a cork helmet by. A single female of the species, in the breeding season, gave M. Camboné about three thousand metres of fine silken thread in about twenty seven days. Small textures woven of these threads are used by the natives for fastening flowers on sunshades and for other light purposes.