The jelly-fishes furnish us with a striking illustration of the profusion of life in the ocean. Provision has indeed been made for securing in all the realms of our globe the largest possible amount of sentient being, and consequently of happiness. And to each tribe a definite part is assigned--a special mission is intrusted. None can be spared from the economy of nature. The shoals of microscopic medusae store up in their own tissues the minute portions of nutritious matter diffused through the waters, and supply food for the support of higher organisms. All the tribes of animated beings are dependent one upon another. That the greatest may enjoy its existence and fulfil its work, the least must hold its place and discharge its function. They co-operate unconsciously to secure the unity and harmony of a system which is designed to promote alike the interests of each and all of them. STEEPLE-JACK'S SECRET. You want me to tell you how it comes to pass that I am able to glide up a steeple like a spider, get astride upon the cross, and pull off my cap to the crowd below, like a gentleman on horseback saluting his acquaintances.[2] You want me to explain on what principle, as you call it, I do this. Well: principle, I suppose, means the rule or law by which a man does what he ought to do; and if so, it is a very good word to use. I will oblige you by explaining my principle, for I am as affable as any man that creeps to his dying day upon the surface of the earth; and I will tell you how it chanced that I found it out: at least I will try, for I am no scholar; and if you wish to understand me, you must have your ears open, and catch a meaning when you can. And this will do you good, whether you make anything out or not. I know fellows that go to the lectures, and come back as empty as they went. But what of that? They think they understand, and thought breeds thought; and when a man's mind is fairly astir, it is odds but something good turns up.