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These are a division of the animal kingdom one step higher in their organization than the infusoria, of which we gave a short account some time ago. They were first observed by M. Leeuwenhoeck, of London, in 1703, in some fresh water ; but since that time we have become aware of their existence in water of all dnds, fresh and salt. The name of " polypi" is derived from two Greek words, signifying many feet, as all of them have a number of long arms or feet (it is scarcely proper to call them either) placed around their mouth, which is in the center of their bodies. Indeed, if you take an india rubber bag, and place a number of strings around its mouth, you have a very good typical polyp. The polypi are not all microscopic, but some attain the size of the cuttle-fish, from which we obtain the beautiful color stpia. This is a dark liquid secreted by the animal, which cannot move very fast ; so when a large fish casts his greedy eye upon him, the cuttlefish squirts out this sepia, and makes a watery cloud so thick around him that the enemy is quite be-fogged, and is glad to escape from so dense a mist, instead of having the meal ho expected. The actinia are members of this division—the beauteous sea anemones ; they fasten themselves to a stone or rock, and spreading out their colored tentacles or arms, wave them gracefully beneath the waves. The eye is never tired of gazing on their elegant motions and gorgeous hues ; they are the most lovely flowers in old Ocean's garden. These are soft-bodied polypi, having no skeleton ; but there are some which make for themselves outside coats of carbonate of lime. Not only do myriads live together in a single concrete house, but so numerous are they that they form islands so large that men can live on them, and animals roam in woods growing on land raised from the sea by a little thing not much larger than a pin's head ; these are the corals, whose history is always interesting, and the story of whose life is the romance of aqueous creation. The most extraordinary of all the polyps' peculiarities is the fact that some of them can be cut up into little bits, and each piece will instantly begin life on its own account, as a new and perfect polyp. They increase by ytm-mination, or the young ones grow like branches from the parent stem, and when they are old enough, disconnect themselves and float away. These arms, with which they are all provided, are their means of offense and defense, and with them they also collect their food, by forcing a current of water down the central aperture of their bodies, or mouth. Some can dilate their mouths to an enormous width, and the sense of touch is very finely developed in them. Some naturalists have thought they have seen traces of a rudimentary eye. The anatomy and life of polyps is a most interesting study, and is calculated in the highest degree to call forth human admiration at the skill and order of their construction and habits. The study of life is always gratifying to living beings, and never more so than when observed in these, the lowest forms
