Page:The Zoologist, 4th series, vol 3 (1899).djvu/383

Rh Similarly an explanation may be long deferred till one branch of science is sufficiently advanced to illuminate another. Discoveries in botany and entomology have often reacted on, and supplemented each other. Prof. Drummond has quoted an instance which will serve our purpose here:—"More than two thousand years ago Herodotus observed a remarkable custom in Egypt. At a certain season of the year the Egyptians went into the desert, cut off branches from the wild palms, and, bringing them back to their gardens, waved them over the flowers of the date palm. Why they performed this ceremony they did not know; but they knew that if they neglected it the date crop would be poor or wholly lost. Herodotus offers the quaint explanation that along with these branches came certain flies possessed of a 'vivific virtue,' which somehow lent an exuberant fertility to the dates. But the true rationale of the incantation is now explained. Palm trees, like human beings, are male and female. The garden plants, the date bearers, were females; the desert plants were males; and the waving of the branches over the females meant the transference of the fertilizing pollen dust from the one to the other."

The time has arrived when the whole theory of "protective resemblance" and (or) "mimicry" requires to be expressed and understood in two senses, viz. Demonstrated, and Suggested or Probable. I propose also to give instances of what may be considered as Disputed or Mistaken Mimicry, and likewise Purposeless Mimicry. In considering these questions one is reminded of the three kinds of Phantasms as understood by the Stoics. Those that were probable, those that were improbable, and those that were neither one nor the other. Or perhaps still better, the three categories of Renan. "The first, which is unfortunately very limited, is the category of certainties; the