The product is elaborated slowly, and must accumulate a little before it reveals its full power.  Taken from her couch and placed elsewhere the female loses her attractiveness for the moment and is an object of indifference; it is to the resting-place, saturated by long contact, that the arrivals fly.  But the female soon regains her power.

The emission of the warning effluvium is more or less delayed according to the species.  The recently metamorphosed female must mature a little and her organs must settle to their work.  Born in the morning, the female of the Great Peacock moth sometimes has visitors the night of the same day; but more often on the second day, after a preparation of forty hours or so.  The Oak Eggar does not publish her banns of marriage before the third or fourth day.

Let us return for a moment to the problematical function of the antennae.  The male Oak Eggar has a sumptuous pair, as has the Great Peacock or Emperor Moth.  Are we to regard these silky “feelers” as a kind of directing compass?—­I resumed, but without attaching much importance to the matter, my previous experiment of amputation.  None of those operated on returned.  Do not let us draw conclusions from that fact alone.  We saw in the case of the Great Peacock that more serious reasons than the truncation of the antennae made return as a rule impossible.

Moreover, a second Bombyx or Eggar, the Clover Moth, very like the Oak Eggar, and like it superbly plumed, poses us a very difficult problem.  It is fairly abundant around my home; even in the orchard I find its cocoon, which is easily confounded with that of the Oak Eggar.  I was at first deceived by the resemblance.  From six cocoons, which I expected to yield Oak Eggars, I obtained, about the end of August, six females of the other species.  Well:  about these six females, born in my house, never a male appeared, although they were undoubtedly present in the neighbourhood.

If the ample and feathery antennae are truly sense-organs, which receive information of distant objects, why were not my richly plumed neighbours aware of what was passing in my study?  Why did their feathery “feelers” leave them in ignorance of events which would have brought flocks of the other Eggar?  Once more, the organ does not determine the aptitude.  One individual or species is gifted, but another is not, despite an organic equality.

CHAPTER XVI

A TRUFFLE-HUNTER:  THE BOLBOCERAS GALLICUS

In the matter of physics we hear of nothing to-day but the Roentgen rays, which penetrate opaque bodies and photograph the invisible.  A splendid discovery; but nothing very remarkable as compared with the surprises reserved for us by the future, when, better instructed as to the why and wherefore of things than now, and supplementing our feeble senses by means of science, we shall succeed in rivalling, however imperfectly, the sensorial acuteness of the lower animals.