The fish often answered to their names when called by their master, or their keeper. The latter, _nomenclator_, made a very handsome income from the admiring crowds, who flocked to see the fish perform their exercises with wagging tails or heads bedecked with rich jewels.[551] Antonia, to whom the lands and villa of Hortensius descended, even stripped herself of her earrings to put them on a _muræna_. This lady, apart from this anecdote, was no ordinary person. We find her passing from the positive of celebrated renown for her beauty, her virtue, her chastity (no mean feat in that day!), through the comparative of being the mother of Germanicus Cæsar and Claudius, and the grandmother of Caligula (which last, in slang parlance, “wanted a bit of doing!”), unto the superlative of deathless fame in Pliny’s “Nunquam exspuisse” (never spat!).[552] The savage use to which Vedius Pollio put his _vivaria_ can be learnt from the pages of Pliny[553] and Seneca.[554] A slave, for breaking a crystal decanter at a banquet given to Augustus, was ordered to be thrown instantly into a _piscina_, there to be eaten alive by the nibbling voracious _Murænæ_. Escaping from his guards he threw himself at the Emperor’s feet, “beseeching nothing else except that he should die otherwise than as food for fish”[555]. Cæsar moved “novitate crudelitatis” (he little knew that this was his host’s cheery custom) commanded the crystals of Pollio to be smashed on the spot, the slave to be freed, and all the fishponds to be filled up. As conducive to _la joie de vivre_ of the other slaves, the command was commendable, for the bite of the _Muræna’s_ serrated teeth, according to Nicander’s _Theriaca_—that “nullius fidei farrago”—owing to its mating with the viper, dealt poisonous death and destruction to the fishermen driven by its pursuit “headlong from their boats,” and was only curable by a mixture made of ashes from its own burnt head! So dreaded was this fish—curious is it not, to read, although from its savage nature no other could inhabit the same _vivarium_, the many stories of its tameness and docility?—that one of the direst of imprecations ran that in the under-world your enemy’s lungs should be mangled by _Murænæ_![556] In times preceding these infatuated extravagant ages, the purpose for which _vivaria_ were first created was steadfastly kept in mind and wonderfully advanced by practical pisciculturists. From being a mere pond for keeping fish alive till needed for the table, _vivaria_ developed in the course of time into spawning grounds. The pisciculturists went even farther. They turned lakes and rivers into natural _vivaria_ by depositing in them not only adult fish, but the spawn of all such species as are in the habit, although born at sea, of pushing some distance up estuaries and streams. Columella instances specially the rivers Velinus, Sabatinus, Ciminus, and Volsinius as examples of the great success of this experiment in fish propagation.[557]