If cost be a true criterion, this preference for salt-water fish continued as late as the fourth century. In Diocletian’s Edict, 301 A.D., fixing the price of food, etc., throughout the Empire, the maximum allowed for best quality sea-fish was nearly double that of best quality river-fish.[465] In both Greece and Rome fish became luxuries of the most expensive kind. Seas and rivers were scoured far and wide. No price was thought too extravagant for a mullet, a sturgeon, or a turbot; three mullets of historical celebrity even fetched in Rome the almost incredible sum of £240![466] In spite of many laws and decrees made at Athens and at Rome (where the Censor often interfered[467] in cases of extravagance in dress, living, etc.) the prices, owing to the ingenuity of the sellers and the wild competition of the buyers, rose constantly higher. The plaint of Cato the Censor that things could not be well with a community, where “a fish fetched more than a bull,” was uttered in and of a generation, which in comparison with its successors looks frugal, even niggardly. Pliny records (_N. H._, IX. 31) “octo milibus nummum unum mullum mercatum fuisse”—one mullet equalled £64, or the price of nine bulls! He also says (_N. H._, IX. 30) that mullets were plentiful and cheap when under 2 lb., “a weight they rarely exceeded.” Martial (_Ep._, XIV. 97) confirms this in his “Do not dishonour your gold serving-dish by a small mullet: none less than two pounds is worthy of it.” In proportion as they exceeded this, they grew in value. One would imagine that Nature had fallen in with the caprice of the Romans, for the fish seems to have grown larger in the decline of the Empire, as if to humour the extravagance of this degenerate people. Horace thought he had pretty well stigmatised the frantic folly of his glutton by a mullet of 3 lbs. (_Sat._, II. 2, 33); but the next reign furnished one of 4½ lbs., which presented to and sold at auction by the Emperor Tiberius was bought by Octavius for £40 (Seneca, _Ep._, XCV. 42), while in Juvenal, IV. 15 f., we have one of 6 lbs.[468] How long the passion for these big mullets lasted it is impossible to tell, but Macrobius, speaking with indignation of one purchased by Asinius Celer in the reign of Claudius for £56 (in Pliny, _N. H._, IX. 31, I find the price was £64!), declares that in his time (fifth century A.D.) such mad prices had vanished. Alongside of Pliny’s caustic comment[469] that the price of a victorious Triumph equalled that of a cook, or a fish, can be set the lament of the Greek comedians that for some fish one had to pay ἴσον ἲσῳ, _i.e._ for weight avoirdupois you handed over a similar weight in money or, as Mayor neatly renders it, “£ for lb.” This gibe at the public mania sprang from bitter personal experience. At Rome, too, we read “of those who sell rare fish for their weight in money.”