85. It only remains for me to say a few words about the origin of this stone. Among the Indians and Persians pearls are found in strong white sea-shells, being created at a regular time by the admixture of dew. For the shells, desiring as it were a kind of copulation, open so as to receive moisture from the nocturnal aspersion. Then becoming big they produce little pearls in triplets, or pairs, or unions, which are so called because the shells when scaled often produce only single pearls, which then are larger. 86. And a proof that this produce arises from and is nourished by some aërial derivation rather than by any fattening power in the sea, is that the drops of morning dew when infused into them make the stones bright and round; while the evening dew makes them crooked and red, and sometimes spotted. They become either small or large in proportion to the quality of the moisture which they imbibe, and other circumstances. When they are shaken, as is often the case by thunder, the shells either become empty, or produce only weak pearls, or such as never come to maturity. 87. Fishing for them is difficult and dangerous, and this circumstance increases their value; because, on account of the snares of the fishermen they are said to avoid the shores most frequented by them, and hide around rocks which are difficult of access and the hiding places of sharks. 88. We are not ignorant that the same species of jewel is also produced and collected in the remote parts of the British sea; though of an inferior value. [138] The book containing this account is lost. [139] From νικάω, to conquer. [140] As the Greek epigram has it-- Τὸν γαίης καὶ πόντου αμειφθείσαισι κελευθοὶς Ναύτην ἠπείρου, πέζόπορον πελάγους. _Thus translated in Bohn's 'Greek Anthology,' p. 25_:-- Him, who reversed the laws great Nature gave, Sail'd o'er the continent and walk'd the wave, Three hundred spears from Sparta's iron plain Have stopp'd. Oh blush, ye mountains and thou main! [141] The probability is that all these names are corrupt. Ammianus's ignorance of the relative bearings of countries makes it difficult to decide what they ought to be. If the proper reading of the last name be, as Valesius thinks, Sarbaletes, that is the name given by Ptolemy to a part of the Red Sea. A French translator of the last century considers the Gulf of Armenia a portion of the Caspian Sea. [142] The Ebro. [143] The Guadalquivir. [144] Ammianus seems to distinguish between the Hyrcanian and Caspian Sea, which are only different names for the same sea or inland lake. [145] A name not very unlike Nejid, to this day the most celebrated Arab breed. [146] There is evidently some corruption here; there is no such Greek word as Machagistia. [147] Il. xiii. 10. [148] A kind of gladiator. BOOK XXIV. ARGUMENT.