The runner, as its name indicates, is a great forager, and is the swiftest and most graceful of all the jacks or cavallies. It ranges farther northward than the other species of the genus. It frequents the reefs and the shores of the keys and mainland of Florida in search of food, which consists of small fishes, as sardines, anchovies, mullets, etc., crustaceans, and other small organisms. It is the best of the jacks as a food-fish, and is in great favor at Key West. For its size it is also the gamest, but as it rarely exceeds a foot in length it is not so much sought, generally, as the larger jacks. It is, however, a great favorite with the juvenile anglers at Key West, as it can be taken from the wharves with almost any kind of bait. On account of its activity and gameness it furnishes fine sport on light tackle, and under these conditions is worthy the attention of the angler. A light black-bass rod, braided linen line, size G, hooks No. 1 or 1-0 on gimp snells, a light multiplying reel and sinker adapted to the tidal current, comprise a good outfit for the runner, which is also known as hard-tail and jurel in some localities. About Key West and the neighboring keys the best bait is the little whirligig mullet (_Querimana gyrans_), which whirls on the surface in large schools, or cut bait or shrimps may be used to advantage. The author of a recently published book on the fishes of Florida makes the following queer statement, "It seems to me the runners are hybrids from the crevalle and bluefish species or families, as they certainly resemble both of those fishes." It would be strange did they not resemble the fishes named, as all are of the mackerel tribe, and all are distinguished by having falcate anal and dorsal fins of about the same relative size, and placed about opposite each other, and also have swallow-shaped caudal fins with slender caudal pedicle; but there the greatest resemblance ends. I have never seen a hybrid among fishes in the natural state. They can be produced by the fishculturist between kindred species, but there is no especial benefit to be derived from such experiments. Hybrids, or so-called mules, are infertile, and incapable of reproducing their kind. THE HORSE-EYE JACK (_Carangus latus_) The horse-eye jack was first described by Louis Agassiz, in 1829, from Brazil, who named it _latus_, or "broad," owing to its short and deep form. It differs from the runner mostly in being deeper in body, and in its large eye. It has a few less soft rays in the dorsal and anal fins, and but thirty-five bony scutes along the lateral line; otherwise it is very similar. Its color is bluish above and golden or silvery below, and it has a black spot on the margin of the gill-cover, but of less size than that of the runner. While it is similar in habits to the runner, it has a more extended range, inhabiting all warm seas.