Page:Figs by Dahlgren, B. E. (Bror Eric).djvu/12

4 "Caprificus" or Caprifig. It is also known as the "male fig" because its figs or flower receptacles contain male flowers in addition to the others. Female trees of the wild fig also exist but are very scarce. The edible fig is undoubtedly derived from such. The male flowers of the Caprifig are situated in the upper part of the fig cavity, immediately below the scales, which here as in the edible fig, bar the opening to intruders.

The insect which ordinarily inhabits the interior of the fig cavity is the minute Fig Wasp (Blastophaga grossorum, family Chalcidae). Through the course of ages of association (fossil figs have been found in remains of the Cretaceous period) the life history of the fig and of the minute wasp have become inextricably entangled. Complete interdependence has been established between them, so that each is necessary for the existence of the other. Without the wasp the wild fig would soon become extinct, for there would be no maturing of seed, and, vice versa, in the absence of the wild figs there would be no fig wasps hatching. The female fig wasp enters the young caprifig in which at a certain period the orifice is relaxed, lays its eggs in the short-styled flowers near the base of the cavity and dies within the fig. These flowers are known as gall flowers. The habit of response to the visitations of the fig wasp has proceeded to the stage of anticipation, for gall flowers are not normal flowers that become gall flowers through the egg-laying of the insect, but are already present as such, though barren and useless till the puncture of the wasp supplies them an inhabitant in the shape of a wasp grub.

The eggs hatch into male and female wasps. The small, yellow, wingless males mature first, bite holes in their galls and crawl out into the cavity of the fig. They soon cut holes in the gall flowers containing the