The fruit of these shell fishes are the Pearles, better or worse, great or small, according to the qualitie and quantitie of the dew which they received. For if the dew were pure and cleare which went into them, then are the Pearles white, faire, and Orient; but if grosse and troubled, the Pearles likewise are dimme, foule, and duskish; pale they are, if the weather were close, darke and threatening raine in the time of their conception. Whereby (no doubt) it is apparent and plaine, that they participate more of the aire and sky, than of the water and the sea; for according as the morning is faire, so are they cleere: but otherwise, if it were misty and cloudy, they also will be thicke and muddy in colour. If they may have their full time and season to feed, the Pearles likewise will thrive and grow bigge: but if in the time it chance to lighten, then they close their shells together, and for want of nourishment are kept hungrie and fasting, and so the pearles keepe at a stay and prosper not accordingly. But if it thunder withall, then suddenly they shut hard at once, and breed only those excrescences which be called _Physemata_, like unto bladders puft up and hooved with wind, no corporal substance at all: and these are the abortive & untimely fruits of these shell fishes.[40] [Illustration: PANAMA SHELL (_Margaritifera margaritifera mazatlanica_) With pearls attached ] [Illustration: VENEZUELA SHELL (_Margaritifera radiata_) Showing growth of pearls ] Pliny’s views were probably derived from the ancient authorities of his time, particularly from Megasthenes, Chares of Mytilene, and Isidorus of Charace; and these curious fictions were incorporated by subsequent writers and influenced popular opinion for many centuries. With scarcely a single exception, every recorded theory from the first century B.C. to the fifteenth century evidences a belief in dew-formed pearls. This theory is referred to by Thomas Moore in his well-known lines: And precious the tear as that rain from the sky, Which turns into pearls as it falls in the sea. The Spanish-Hebrew traveler Benjamin of Tudela, in his “Masaoth” in Persia (from 1160 to 1173), wrote: “In these places pearls are found, made by the wonderful artifice of nature: for on the four and twentieth day of the month Nisan, a certain dew falleth into the waters, which being sucked in by the oysters, they immediately sink to the bottom of the sea; afterwards, about the middle of the month Tisri, men descend to the bottom of the sea, and, by the help of cords, these men bringing up the oysters in great quantities from thence, open and take out of them the pearls.”[41] From the “Bustan,” one of the most popular works of Sadi, the Persian poet (1190–1291 A.D.), Davie quotes: