[2611] See B. vi. c. [2]3. Ælian, Hist. Anim. B. xv. c. 8, says to the same effect, but calls it “Perimuda, a city of India.”
[2612] Ælian, Hist. Anim. B. x. c. 13. It has been already remarked, in the sixth Book, that the ancients looked upon the Persian Gulf as forming part of the Erythræan or Red Sea.
[2613] The pearl itself, Cuvier says, is nothing else but an extravasation, so to say, of the juices, whose duty it is to line the interior of the shell, to thicken and so amplify it; and consequently, it is produced by a malady. It is possible, he says, for them to be found in all shell-fish; but they have no beauty in them, unless the interior of the shell, the nacre, or, as we call it, the mother of pearl, is lustrous and beautiful itself. Hence it is, that the finest of them come from the east, and are furnished by the kind of bivalve, called by Linnæus, “Mytilus margaritiferus,” which has the most beautiful mother of pearl in the interior that is known. The parts of the Indian sea which are mentioned by Pliny, are those in which the pearl oyster is still found in the greatest abundance.
[2614] All this theory, as Cuvier says, is totally imaginary.
[2615] Isidorus of Charax, in his description of Parthia, commended by Athenæus, B. iii., says, on the other hand, that the fish are aided in bringing forth, by rain and thunder.
[2616] From the Greek φυσήμα, “air-bubble.”
[2617] It sometimes happens, Cuvier says, that the secretion which forms the mother-of-pearl makes tubercles in the interior of the shell, which are the pearls adhering to the shell here spoken of.
[2618] Persius alludes to this in Sat. ii. l. 66. “Hæc baccam conchæ rasisse;” “to file the pearl away from its shell.”
[2619] From this passage we learn that the “tympana,” or hand-drums of the ancients, were often of a semiglobular shape, like the kettle-drums of the present day.
[2620] Cuvier remarks that this is not the fact: the concretions are perfectly hard before the animal leaves the water.