The route from Uritucu through the Steppe was formerly obliged to be changed, because the gymnoti had increased to such numbers in a small stream that in crossing it many horses were drowned every year, either from the effects of the shocks they received, or from fright. All other fishes fly the vicinity of these formidable eels. Even the fisherman angling from the high bank fears lest the damp line should convey the shock to him from a distance. Thus, in these regions, electric fire breaks forth from the bosom of the waters. The capture of the gymnoti affords a picturesque spectacle. Mules and horses are driven into a marsh which is closely surrounded by Indians, until the unwonted noise and disturbance induce the pugnacious fish to begin an attack. One sees them swimming about like serpents, and trying cunningly to glide under the bellies of the horses. Many of these are stunned by the force of the invisible blows; others, with manes standing on end, foaming and with wild terror sparkling in their eyes, try to fly from the raging tempest. But the Indians, armed with long poles of bamboo, drive them back into the middle of the pool. Gradually the fury of the unequal strife begins to slacken. Like clouds which have discharged their electricity, the wearied fish begin to disperse; long repose and abundant food are required to replace the galvanic force which they have expended. Their shocks become gradually weaker and weaker. Terrified by the noise of the trampling horses, they timidly approach the bank, where they are wounded by harpoons, and cautiously drawn on shore by non-conducting pieces of dry wood. Such is the extraordinary battle between horses and fish. That which forms the invisible but living weapon of this electric eel;--that which, awakened by the contact of moist dissimilar particles,[43] circulates through all the organs of plants and animals;--that which, flashing from the thunder cloud, illumines the wide skyey canopy;--that which draws iron to iron and directs the silent recurring march of the guiding needle;--all, like the several hues of the divided ray of light, flow from one source; and all blend again together in one perpetually, every where diffused, force or power. I might here close the hazardous attempt to trace a picture of nature such as she shows herself in the Steppes. But as on the ocean fancy not unwillingly dwells awhile on the image of its distant shores, so, before the wide plain disappears from our view, let us cast a rapid glance at the regions by which the Steppes are bounded.