Another excellent fish for the table is the Pike-Perch, (_Lucio-Perca_) or Glass-Eyed Pike, from his large, brilliant eyes. In Ohio, it is called the salmon, and by the Canadians the pickerel, while, with singular perversity, they persist in calling our pickerel a pike. It is a very firm, well-flavored fish, weighing from two to ten pounds, and is found in all the Great Lakes. Professor Agassiz was the first to describe a large and valuable species of pike, which he found in Lake Superior,--the Northern Pike (_Esox Boreus_). This is the most common species of pike in the St. Lawrence basin, though usually confounded with the common pickerel (_Esox Reticulatus_). It grows to the size of fifteen or twenty pounds, and is a better table-fish than _Esox Reticulatus_. It may be distinguished by the rows of spots sides, of a lighter color than the ground upon which they are arranged. It differs from the Muskelunge in having the lower jaw full of teeth; whereas in the Muskelunge the anterior half of the lower jaw is toothless. All the streams which empty into Lake Superior, those of the north shore of Lake Huron, the west shore of Lake Michigan as far as Lake Winnebago, and all the streams of Lake Ontario, contain the Speckled Trout (_Salmo Fontinalis_); while they are not found in the streams on the southern coasts of Lake Michigan, or (so far as we know) in the streams of Lake Erie. What can determine this limitation of the range of the species? It cannot be latitude, since trout are found in Pennsylvania and Virginia. It is not longitude, since they occur in the head-waters of the Iowa rivers. So Professor Agassiz found that Lake Superior contained species which were not to be found in the other lakes, and that the other lakes, again, contained species which did not occur in Lake Superior. He says, in his work on Lake Superior, "It is the great question of the unity or plurality of creations; it is not less the question of the origin of animals from single pairs or in large numbers; and, strange to say, a thorough examination of the fishes of Lake Superior, compared with those of the adjacent waters, is likely to throw more light upon such questions, than all traditions, however ancient, however near in point of time to the epoch of Creation itself." In Lake Superior is likewise found that remarkable salmon, the Siscowet,--which is so fat and luscious as to be uneatable in a fresh state, and requires to be salted to render it fit for food. It commands a much higher price by the barrel than the lake-trout or white-fish, and is rarely to be met with out of the Lake cities. In this basin is also found the Gar-Pike, (_Lepidosteus,_) a singular animal, which is the only living representative of the fishes that existed in the early ages of the earth's history,--and which, by its formidable array of teeth, its impenetrable armor, and its swiftness and voracity, gives us some idea of the terrible creatures which peopled the waters of that period.