The Outline of Science, Volume 1

In adaptation to the great pressure the bodies of deep-sea animals are usually very permeable, so that the water gets through and through them, as in the case of Venus' Flower Basket, a flinty sponge which a child's finger would shiver. But when the pressure inside is the same as that outside nothing happens. In adaptation to the treacherous ooze, so apt to smother, many of the active deep-sea animals have very long, stilt-like legs, and many of the sedentary types are lifted into safety on the end of long stalks which have their bases embedded in the mud. In adaptation to the darkness, in which there is only luminescence that eyes could use, there is a great development of tactility. The interesting problem of luminescence will be discussed elsewhere. As to the origin of the deep-sea fauna, there seems no doubt[Pg 125] that it has arisen by many contributions from the various shore-haunts. Following the down-drifting food, many shore-animals have in the course of many generations reached the world of eternal night and winter, and become adapted to its strange conditions. For the animals of the deep-sea are as fit, beautiful, and vigorous as those elsewhere. There are no slums in Nature. THE BITTERLING (Rhodeus Amarus) A Continental fish which lays its eggs by means of a long ovipositor inside the freshwater mussel. The eggs develop inside the mollusc's gill-plates. Photo: W. S. Berridge. WOOLLY OPOSSUM CARRYING HER FAMILY One of the young ones is clinging to its mother and has its long prehensile tail coiled round hers. SURINAM TOAD (Pipa Americana) WITH YOUNG ONES HATCHING OUT OF LITTLE POCKETS ON HER BACK STORM PETREL OR MOTHER CAREY'S CHICKEN (Procellaria Pelagica) This characteristic bird of the open sea does not come to land at all except to nest. It is the smallest web-footed bird, about four inches long. The legs are long and often touch the water as the bird flies. The storm petrel is at home in the Atlantic, and often nests on islands off the west coast of Britain.