Nature's Storehouses.

New Zealand Illustrated Magazine, Volume V, Issue 2, 1 November 1901, Page 95

Nature's Storehouses.

By Ambrose Quail, P.E.S. (London)

fHE position and composition of the rocks, which constitute the earth, prove that the land surface of the whole world has undergone continual change and alteration. During the formation of the rocks, the form of things then living, having become embedded, their fossil remains have been preserved, aud prove that almost all forms of life have undergone continual change and alteration. The. rocks have been associated together, according to position, mineral, and fossil characters, by geologists, and form more or less definite periods. Thus below the earth there is a veritable storehouse of things as they have been.

The preservation in the locks of such soft-bodied organisms, as the earliest forms probably were, is not to be expected ; nor do we find any undoubted organic remains in the Laurentian — the most ancient sedi-

mentary rocks. These, however, appear to have been altered largely by great heat, and converted into crystalline composition, probably by contact with other (volcanic) rocks in a molten condition, especially at the base of the series. At the base of the next series of rocks, which are less altered, there have been found — in Europe — what are probably the earliest

fossil remains, consisting of such soft-bodied tilings as sponges. In other nicks of the Cambrian period there are more numerous fossils of seaweeds, sponges, corals, shells, trilobites, and even jelly fish, and wormiike tracks and burrows ; some of the latter were probably made by trilobites, as their numerous backward spines might compel them to move only in a forward direction in the mud of the sea bottom.

Speaking of life on tho earth al this neriod, Professor Button h.'i.s said: — "The rocks below lowwater murk would be covered with delicate red and

brown son wax I a and the ocean b etweon tide mar lc h wou I d then, as now, l>o gird led with a bolt of vivid green, but all the land above would be bv o w n an d barren, without even a moss or lichen growing on it. Upon the Bands might lie a dead jelly fish,

or trilobite, or perhaps a delicate transparent shell thrown up by the waves, but these would be rarely seen, and the great ocean, although really swarraiug with minute life, would to the naked eye appear tenantless." In rocks of the Silurian period there are numerous coral remains as of shallow seas, ripple marks as of tides, and pebbles of seashores. The marine remains are more

diversified than hitherto, aud among the shellfish ai'e forms, from which others of later date may have been derived. Trilobites attain the size of eighteen inches, and other crustacean animals abound, and there are fossil remains of fishes' teeth, but the early fish forms were probably too soft to be preserved. The land was not now barren, as moss, twigs, and seed spores of land plants have been preserved iv the upper rocks of this period. The lower rocks of the Devonian period contain remains of enormous lobster-like crustaceans several feet in length ; but the fishes are most numerous, of great diversity, and agree in the tails having a prolonged lobe extension of the backbone. It is interesting to observe the early form of fish tail and later developments. On the land marshes and river bauks there grew leeds, ferns, and such plant life, of which fossils remain, though not specially numerous. The low - lying marshlands of the Oai'boniferous period were overgrown by an exuberant land vegetation, mosses, ferns, tree ferns, pine trees of gigantic size. Constant volcanic action, frequent inundation from the rivers and shallow seas, submerged and buried the vegetation, which has become the coal beds of the present day. Other coal beds were developed at later periods but never so extensively. Amongst the reeds of the marshlands amphibious reptiles Jaid wait for other animals of the seas and rivers, and their fossil excrement contains fish-scales and other matter, showing the nature of their prey. The Permian period marks the disappearance of many forms of life such as trilobites, many other crustaceans, and many fish forms. The fossils of the period, though not so numerous, ai'e similar to the preceding. True air breathing lizards and such like animals now inhabit the land amongst the ferns, reeds and palms.

Frequent disturbances of laud areas appear to have produced a scarcity of life form in the Triassic period ; such as have been preserved resemble the forms of later date more than any preceding period. From this

time onward living things became gradually like those of the present day. Fish, with tails having equal lobes, gradually replace those with unequal lobes. Small land mammals appeared ; reptiles were still most numerous. Reptiles attain enormous proportions and great diversity during the Jui'assic period in the sea, ou the land, and even flying in the air. Two specimens of an early form of bird life have been found, in which the backbone has a jointed tail (like reptiles) with feathers attached as in true birds. The sea shells of the period were beautiful in sculpture and shape. There are many interesting forms of sea shells in the Cretaceous or Chalk period ; reptiles similar to the preceding, and fish similar to those of the present day. Many fish, which inhabited the shallow seas of former periods, became fresh water and deep sea fish, where some still survive. The Tertiary period immediately preceded the pi'esent or historical times. Reptile life decreased, but the ancestors of living mammals may be traced in the Tertiary rocks. The early forms were small, but with many characters of existing animals in a primitive condition. The horse, deer, pig of to-day can be traced to ancestors with several toes. Hornless rhinoceros preceded those with the horn. The largest animals of the present day, such as elephants, etc., do not equal in size or development some of the animals of the late Tertiary period, as the mammoth, mastodon, toxodon, megatherium and many others.

Some organisms have probably existed since the earliest time with little or no alteration. Many higher organisms have certainly passed away during the lapse of ages, and given place to others more suited to altered conditions, which prevailed from time to time. The world is to-day inhabited .by descendants of all these past forms of life, whilst every river in every land, and the sea everywhere, are tearing away the land and pounding and grinding the material which will form new rocks and add to Nature's Storehouse.