Moreover, they are quite as much at home in the depths of the sea, with miles of water piled over their heads, as on shelving beaches near to land. During the _Challenger_ Expedition crabs were fished up from all depths--from one mile, two miles, three miles, even between three and four miles. In those dark and icy regions the cold must be great, the pressure tremendous; still crabs innumerable are there. Some sub-ocean kinds have displayed what may be looked upon as an inquiring disposition. A ship passing near the Azores brought up in a trap many large ones, belonging to a then new species. And the curious part of the matter was that not all of them need have come. Some were entrapped, and could not get away; but others rose to the surface of their own free will, clinging to the outside of the trap, and not attempting to escape, even when drawn out of the water, and on deck. Perhaps they were dazzled by the unaccustomed brightness of light, after the few and feeble glimmers below. But the puzzle remains--why, in the beginning, they should have chosen to leave their home, and to journey upward into unknown regions? Were they of an aspiring character? Had they friends caught in the net, from whom they would not be parted? Or was the attraction merely that of the appetising food which those friends were enjoying? An interesting haul was one day made by the _Challenger_ while crossing the Bay of Biscay; not indeed from a great depth, since the Bay is in no part very profound, but from the sea-bed. More than five thousand small sharp-clawed crabs came up in company; and they took quite kindly to the new conditions of life on board. They cheerfully explored the whole vessel, turning up in every direction, during the next few days. Something in the nature of a love for home has been shown by crabs, at least in one instance. Many years ago a singular story to this effect was told in a scientific paper.[8] [8] _Nature_, April 3rd, 1873. The fishermen of Falmouth, capturing crabs off the rocks at Lizard Point, brought them by boat to Falmouth Harbour, and kept them there till needed, in a box sunk under water, some four miles out. Each crab had been branded on the back with its owner’s mark. By accident one of these boxes was broken; and all the prisoners made good their escape. Naturally, no one expected to see them again. But only two or three days later those very same crabs--with branded carapaces--were caught anew by the fishermen; not near Falmouth, but as before, off the Lizard. How they had managed to get there, how they had first found their way to Falmouth Harbour, a distance of four miles, and then for miles more along the coast, are questions more easily put than answered. The word “instinct” fails to meet the difficulty. One thing only is clear, that they preferred the neighbourhood to which they were accustomed. Very fearless creatures are small crabs, generally; brave, no doubt, partly because of their numbers.