One singular propensity of the mullet[2398] has afforded a subject for laughter;[2399] when it is frightened, it hides its head, and fancies that the whole of its body is concealed. Their salacious propensities[2400] render them so unguarded, that in Phœnicia and in the province of Gallia Narbonensis, at the time of coupling, a male, being taken from out of the preserves, is fastened to a long line, which is passed through his mouth and gills; he is then let go in the sea, after which he is drawn back again by the line, upon which the females will follow him to the very water’s edge; and so, on the other hand, the male will follow the female, during the spawning season. CHAP. 27.—THE ACIPENSER. Among the ancients, the acipenser[2401] was esteemed the most noble fish of all; it is the only one that has the scales turned towards the head, and in a contrary direction to that in which it swims. At the present day, however, it is held in no esteem, which I am the more surprised at, it being so very rarely found. Some writers call this fish the elops. CHAP. 28.—THE LUPUS, ASELLUS. At a later period, they set the highest value on the lupus[2402] and the asellus,[2403] as we learn from Cornelius Nepos, and the poet, Laberius, the author of the Mimes. The most approved kinds of the lupus are those which have the name of “lanati,” or “woolly,” in consequence of the extreme whiteness and softness of the flesh. Of the asellus there are two sorts, the callarias, which is the smallest, and the bacchus,[2404] which is only taken in deep water, and is hence much preferred to the former. On the other hand, among the varieties of the lupus, those are the most esteemed which are taken in rivers. CHAP. 29.—THE SCARUS, THE MUSTELA. At the present day, the first place is given to the scarus,[2405] the only fish that is said to ruminate, and to feed on grass and not on other fish. It is mostly found in the Carpathian Sea, and never of its own accord passes Lectum,[2406] a promontory of Troas. Optatus Elipertius, the commander of the fleet under the Emperor Claudius, had this fish brought from that locality, and dispersed in various places off the coast between Ostia and the districts of Campania. During five years, the greatest care was taken that those which were caught should be returned to the sea; but since then they have been always found in great abundance off the shores of Italy, where formerly there were none to be taken. Thus has gluttony introduced these fish, to be a dainty within its reach, and added a new inhabitant to the seas; so that we ought to feel no surprise that foreign birds breed at Rome. The fish that is next in estimation for the table is the mustela,[2407] but that is valued only for its liver. A singular thing to tell of—the lake of Brigantia,[2408] in Rhætia, lying in the midst of the Alps, produces them to rival even those of the sea.[2409] CHAP. 30.—THE VARIOUS KINDS OF MULLETS, AND THE SARGUS THAT ATTENDS THEM.