1 70 PROF. T. R. JONES IMPORTANCE OF 



little nodule of chalcedony. This Wealden limestone from Mount- 

 field is full of Ci/pridce, but they are so closely cemented that they 

 are disclosed only on the weathered surface. Thus one of the rocks 

 formerly used for lime-making in Sussex is composed of Cypridce. 

 Some of the Swanage building- stone is also wholly composed of 

 them. Many of the dangerous promontories, reefs, and skerries 

 on the south coast of the Isle of Wight, where so many 

 of the old East-Indiamen and other vessels have been wrecked, 

 would not have been there if it had not been for the Cy- 

 pridcB ; for where they abounded in the old fluviatile and estuarine 

 muds which have become the Wealden strata, they gave up the 

 lime of their shells to the mud, making numerous layers here and 

 there in the thick clays into hard bands of rock. These remained, 

 edge-on to the present sea-board, when the clays were washed away. 

 Thus the muds, hardened by the calcareous material of these tiny 

 atoms, have formed persistent reefs, helping to keep up the island, 

 but wrecking large ships and small, with great misfortune to 

 hundreds of families. 



There are other creatures among the Microzoa, which occur 

 in great abundance ; more particularly one set, of calcareous struc- 

 ture, called Foraminifera. The name Globigerina has become 

 almost a household word since these animalcula were found abun- 

 dantly in laying the Atlantic cable. They add very largely to the 

 material at the bottom of the ocean. Here is a sketch of the 

 Atlantic ooze (a whitish sticky mud, when fresh) as seen under the 

 microscope, with whole and fragmentary shells of GlohiyeruKS and 

 other Foraminifera {Pidvinulina and Orlulina) constituting the 

 material. Glohigerinm are obtained from great depths in the Atlantic, 

 the Pacific, the Indian Ocean, E,ed Sea, and Australian waters, 

 where they form there is no knowing how thick a mass. They 

 are also found in shallow water in the Adriatic and elsewhere ; 

 and some are found floating at or near the surface of the ocean. 

 Besides the white ooze, there are wide tracts of Diatomaceous earth 

 and Polycystine ooze on the ocean-floor ; also wide areas of red mud, 

 from the decomposition of volcanic ashes, and alluvial deposits near 

 the river-mouths. The Globigerina-ooze is somewhat like the 

 Chalk ; but the component shells and Foraminifera ditf er to a great 

 extent. 



The Foraminifera belong to a group of animalcules, called 

 Protozoa, which consist of a little jelly-like mass — a minute gela- 

 tinous atom, having the faculty of moving and of feeding itself 

 without the aid of the limbs and apparatus of the higher animals. 

 The flesh is not really flesh, but, as it must have a name, it is called 

 " sarcode ; " it is also called "protoplasm," because it is the 

 simplest form of living material. The well-known Amoeba can 

 extend and retract any portion of its body, and moves on almost 

 like a speck of thick mucilage. When it comes to a particle suited 

 for its food, it incloses it — making a temporary stomach — and 

 digests or uses it up, except refractoiy grains, and they are got 

 rid of by being passed off through some part of the body. Some 



