The facts are; first that water, being all but incompressible, is hardly any heavier, and just as liquid, at the greatest depth, than at the surface; and that therefore animals can move as freely in it in deep as in shallow water; and next, that as the fluids inside the body of a sea animal must be at the same pressure as that of the water outside it, the two pressures must balance each other; and the body, instead of being crushed in, may be unconscious that it is living under a weight of two or three miles of water. But so it is; as we gather our curiosities at low-tide mark, or haul the dredge a mile or two out at sea, we may allow our fancy to range freely out to the westward, and down over the subaqueous cliffs of the hundred-fathom line, which mark the old shore of the British Isles, or rather of a time when Britain and Ireland were part of the continent, through water a mile, and two, and three miles deep, into total darkness, and icy cold, and a pressure which, in the open air, would crush any known living creature to a jelly; and be certain that we shall find the ocean-floor teeming everywhere with multitudinous life, some of it strangely like, some strangely unlike, the creatures which we see along the shore. Some strangely like. You may find, for instance, among the sea-weed, here and there, a little black sea-spider, a Nymphon, who has this peculiarity, that possessing no body at all to speak of, he carries his needful stomach in long branches, packed inside his legs. The specimens which you will find will probably be half an inch across the legs. An almost exactly similar Nymphon has been dredged from the depths of the Arctic and Antarctic oceans, nearly two feet across. [Picture: Nymphon Abyssorum, Norman] You may find also a quaint little shrimp, _Caprella_, clinging by its hind claws to sea-weed, and waving its gaunt grotesque body to and fro, while it makes mesmeric passes with its large fore claws,—one of the most ridiculous of Nature’s many ridiculous forms. Those which you will find will be some quarter of an inch in length; but in the cold area of the North Atlantic, their cousins, it is now found, are nearly three inches long, and perch in like manner, not on sea-weeds, for there are none so deep, but on branching sponges. These are but two instances out of many of forms which were supposed to be peculiar to shallow shores repeating themselves at vast depths: thus forcing on us strange questions about changes in the distribution and depth of the ancient seas; and forcing us, also, to reconsider the old rules by which rocks were distinguished as deep-sea or shallow-sea deposits according to the fossils found in them. [Picture: Caprella spinosissima, Norman]