The next step in the ascending scale of life-forms is occupied by the _polyps_, which are found in water, fastened to floating matter. The polyps fasten themselves to this floating matter, with their mouths downward, from the latter dangling certain tentacles, or thin, long arms. These tentacles contain small thread-like coils in contact with a poisonous fluid, and enclosed in a cell. When the tentacles come in contact with the prey of the creature, or with anything that is sensed as a possible enemy, they contract around the object and the little cells burst and the tiny thread-like coils are released and twist themselves like a loop around the object, poisoning it with the secreted fluid. Some of the polyps secrete flint-like tubes, which they inhabit, and from the ends of which they emerge like flowers. From these parent polyps emerge clusters of young, resembling buds. These bud-like young afterwards become what are known as jelly-fishes, etc., which in turn reproduce themselves--but here is a wonder--the jelly-fish lay eggs, which when hatched produce stationary polyps like their grandparent, and not moving creatures like their parents. The jelly-fishes have a comparatively complex organism. They have an intricate system of canal-like passages with which to convey their food and oxygen to the various parts. They also have something like muscles, which contract and enable the creature to "swim." They also possess a "nervous system," and, most wonderful of all, they have _rudimentary eyes and ears_. Their tentacles, like those of the parent-polyp, secrete the poisonous fluid which is discharged into prey or enemy. Akin to the polyps are the sea-anemones, with their beautiful colors, and still more complex structure and organism, the tentacles of which resemble the petals of a flower. Varying slightly from these are the coral-creatures, which form in colonies and the skeletons of which form the coral trees and branches, and other forms, with which we are familiar. Passing on to the next highest family of life-forms, we see the spiny-bodied sea-creatures, such as the sea-urchin, star-fish, etc., which possess a thick, hard skin, covered by spines or prickly projections. These creatures abound in numerous species. The star-fish has rays projecting from a common centre, which gives it its name, while the sea-urchin resembles a ball. The sea-lilies, with their stems and flowers (so-called) belong to this family, as do also the sea-cucumbers, whose name is obtained from their shape and general appearance, but which are animals possessing a comparatively complex organism, one of the features of which is a stomach which may be discarded at will and replaced by a new one. These creatures have a well defined nervous system, and have eyes, and some of them even rudimentary eyelids.