_Anguilla rostrata_, as the Common American Eel is technically known, is abundant in the United States, living in fresh-water streams, but depositing its eggs, often eight millions to a single fish, in the ocean, the young ascending the rivers. Eels are devoid of ventral fins. Their scales, which are very minute, are covered with a thick, slime-like material. Under the microscope each scale is beautifully ornamented, and the exquisite pattern formed by the scales on the skin may be readily and effectively seen if a bit of it, when fresh, be placed on the window-glass and allowed to dry. The sexes are difficult to distinguish; the females have the highest dorsal fin, smaller eyes, and a lighter color than the males, while the snout is generally broader at the tip. When contiguous to the sea, as in a pond near Wells, on the coast of Maine, the Eels invariably go down into salt water at night. As the connecting stream is narrow, the sight is remarkable, thousands filling the channel, many of whom, when alarmed, leaving the water and passing over the dry rocks to the ocean. Eels are not the silent creatures which many persons suppose them to be. They frequently utter a sound, expressed by a single note, which is more distinctly musical than the sounds made by other fishes, and which has a clear metallic resonance. They are of slow growth, scarcely reaching the length of twelve inches during the first year, but subsequently attaining to large dimensions, the preserved skins of two Eels, which Mr. Yarrall saw at Cambridge, England, weighing together fifty pounds, the heavier being twenty-seven pounds in weight. [Illustration: COMMON AMERICAN EEL. How It Seeks New Feeding-Grounds.] Fish, as a rule, do not live more than a few minutes out of the water. An Eel, however, will remain alive for many hours, and even days, in atmospheric air, provided it is laid in a damp place. Now, if one be carefully watched when placed upon dry land, it will be observed to pout out the cheeks on both sides of its face. Underneath this puffed-out skin will be found the gills, and the skin which covers them will be seen to be so arranged as to form a closed sac, which the Eel fills with water, and so keeps the gill-fibres moist. This wonderful contrivance enables the Eel to come out of the water, and to travel, so to speak, by land. Thus Eels are often found in outlying ponds of human construction, where they were never placed by the hand of man. Finding old quarters uncomfortable, they take in a good supply of water, and exchange them for the better, not by repeated leaps towards the water, as some fish are known to do, but by a smooth, uniform snake-like progression.