But while we may dispute about the highest fish, there is no doubt about the lowest one. This is the lancelet. It is of the size and shape of a toothpick, translucent, scaleless, and almost finless, burying itself in the sand on warm coasts, in almost every region.

The lancelet has no real bone in it, just a line of soft tissue blocking out the space where the backbone ought to be. It has no skull, nor brain, nor eyes, nor jaws, nor heart, nor anything in particular — just transparent muscle, spinal cord, artery gills, stomach and ovaries, with a fringe of feelers about the slit we call the mouth. And even these organs are rather blocked out than developed, yet it is easy to see that the creature is a vertebrate in intention and therefore essentially a fish — a fish and a vertebrate reduced to their lowest terms.

You can go fishing almost anywhere, but whether it is good to do it or not depends on your reasons for doing it. There are about three good reasons for going a-fishing, one indifferent one, and one that is wholly bad.

One good reason is that you may learn to know fish. Isaac Walton tells us that "it is good luck to any man to be on the good side of the man that knows fish." This is true, but you cannot learn to know fish unless you go forth to find them. There are about 15,000 kinds of fish in the world; 4,000 of them in North America, north of Panama. Now no man knows them all, not even on one continent, though some have written books upon them.

But the man who knows a large part of them has not only learned fish, but a host of other things as well. He calls to mind rosy-spotted trout of the Maine woods, and still rosier of many brooks of Unalaska. He has seen the blue parrot fishes of the Cub an reefs and the leaping grayling of the Gallatin and the Au Sable. He has tried the inconnu of the Mackenzie River and the tarpon of the Florida reefs. He knows the sparkling darters of the french broad and the Swannanoa, the clear-skinned pescados blancos of the Chapala Lake and the pop-eyes and grenadiers of three miles drop of Bering Sea.

Till you learn to know fish you cannot imagine what the water depths still have for you to know.

The second good reason why you should go a-fishing is that you may know ,the places where fishes go. All the finest scenery is full of fish. The Fire-Hole Canyon, the Roaring River, the Agna Bonita, the Rio Blanco, de Orizaba, the creek of Captains Harbor, the Saranna, the Roanoke, the Restigouche, the Nipigon, and the lakes of the St. John, all these are good fishing water of their kind. So is the Rio Almendares, the Twin Lakes, and the Eagle River, the Sawtooth Mountains, the Venados Islands, the shores of Clipperton, the Pearl Islands, Dead Man's Reef, No Man's Land, and the sand reaches of San Diego, Santa Barbara, Pensacola, and Beaufort. If you know all these you know the rest of the United States, with Canada and Mexico as well. All this is a goodly country, which it is well for a good citizen to understand.

If you go a-fishing to know the fish, the rest will be granted to you. And with all the rest you have filled your mind not only with pictures of plunging trout, of leaping muscallonge and diving barracuda, but you have enriched it with endless vistas of deep, green pools; of foamy cascades, flower-carpeted meadows, of dark pines and sunny pines, white birch and clinging vines and wallowing mangrove. You have "dominion over palm and pine," the only dominion there is; for your dominion doth not "speedily pass away." You know the crescent bay, with its white breakers, the rush of the eager waters through the tide-worn estuary, the clinging fucus on the rocks at low tide, the bark of sea wolves, and the roar of sea lions in the long lines of swaying kelp which reach far out into the farthest sea. This is good for you to know, for it is an antidote to selfishness and doubt and care. Then, too, it is good to know the men that live in the open where the fishes are. To shake their hands and share their hospitality will cure you of pessimism and distrust of democracy, and banish all the chimeras and goblins which vex those who live too long in cities. To hear the elk's whistle and the ouzel's call, the whirr of the grouse's wings and the rush of the water in the canyon, will get out of your brain the shriek of cable cars, the rattle of the elevated railway, and all the unwholesome jangle of men who meet to make money.