My Studio Neighbors

What a singular decree has Nature declared with reference to the milkweed! She says, in plainest terms, "Your pollen must be removed on the leg of an insect, preferably a bee, or your kind shall perish from the face of the earth." And what is the deep-laid plan by which this end is assured? My specimens here on the desk will disclose it all. Here are two bees, a fly, and a beetle, each hanging dead by its legs from a flower, an extreme sacrificial penalty, which is singularly frequent, but which was certainly not exacted nor contemplated in the design of the flower. A careful search among almost any good-sized cluster of milkweeds will show us many such prisoners. As in all flowers, the pollen of the milkweed blossom must come in contact with its stigma before fruition is possible. In this peculiar family of plants, however, the pollen is distinct in character, and closely suggests the orchids in its consistency and disposition. The yellow powdery substance with which we are all familiar in ordinary flowers is here absent, the pollen being collected in two club-shaped or, more properly, spatula-shaped masses, linked in pairs at their slender prolonged tips, each of which terminates in a sticky disc-shaped appendage united in V-shape below. These pollen masses are concealed in pockets (B) around the cylindrical centre of the flower, the discs only being exposed at the surface, at five equidistant points around its rim, where they lie in wait for the first unwary foot that shall touch them. A glance at the two views of this central portion of the flower, as it appears through my magnifying-glass--the honey-horns and sepals having been removed--will, I think, indicate its peculiar anatomy or mechanism. No stigma is to be seen in the flower, the stigmatic surface which is to receive the pollen being concealed within five compartments, each of which is protected by a raised tent-like covering, cleft along its entire apex by a fine fissure (A). Outside of each of these, and entirely separated from the stigma in the cavity, lie the pollen masses within their pockets, each pair uniting at the rim below in V-shape, the union at the lower limit of the fissure.