with a thin, brown, wrinkled, papery membrane, which is its own coat—the seed-coat, or testa (Fig. 2, t). The extent to which the testa remains adherent to the seed, or to the inner coat of the pericarp, and both together to the harder outer coat of the pericarp, need not be
commented upon further than to say that differences in this respect are found according to the completeness and ripeness of the acorn.
Enveloped in its testa and in the pericarp, then, we find the long acorn-shaped seed, which seems at first to be a mere horn-like mass without parts. This is not the case, however, as may easily be observed by cutting the mass across, or, better still, by first soaking it in water for some hours; it will then be found that the