It is not intended to enter into a defense of the local pool known as the New York Stock Exchange. It needs none. Some regard it as a necessary standpipe to promote and equalize distribution, others consult it as a sort of Nilometer, to note the rise and fall of the waters and the probabilities of drought or flood. Everybody knows that it is full of the most gamy and beautiful fish in the world--namely, the speckled trout, whose honest occupation it is to devour whatever is thrown into the pool--a body governed by the strictest laws of political economy in guarding against over-population, by carrying out the Malthusian idea, in the habit the big ones have of eating the little ones. But occasionally this harmonious family, which is animated by one of the most conspicuous traits of human nature--to which we owe very much of our progress--namely, the desire to get hold of everything within reach, and is such a useful object-lesson of the universal law of upward struggle that results in the survival of the fittest, this harmonious family is disturbed by the advent of a pickerel, which makes a raid, introduces confusion into all the calculations of the pool, roils the water, and drives the trout into their holes. The presence in the pool of a slimy eel or a blundering bullhead or a lethargic sucker is bad enough, but the rush in of the pickerel is the advent of the devil himself. Until he is got rid of, all the delicate machinery for the calculation of chances is hopelessly disturbed; and no one could tell what would become of the business of the country if there were not a considerable number of devoted men engaged in registering its fluctuations and the change of values, and willing to back their opinions by investing their own capital or, more often, the capital of others. This somewhat mixed figure cannot be pursued further without losing its analogy, becoming fantastic, and violating natural law. For it is matter of observation that in this arena the pickerel, if he succeeds in clearing out the pool, suddenly becomes a trout, and is respected as the biggest and most useful fish in the pond.