Trace the Process of Life.

All organisms arise out of structureless albumenoid living matter, which in the primal state not living at all, received the first touch of life. The essential principles of every change, active moving, enter, reside, and work, for the most part, from within. The masses of protoplasm, sarcode, bioplasm-call them what you will-undergo division. The definite size being obtained, which varies in different creatures and textures, but is constant for the same, portions move away; and, at length, detach themselves. The earliest stages of organisms possess the greatest number of similarities. Somewhat further on, the characters are those belonging to a smaller number of organisms. At every advance, traits are acquired which successively distinguish group from group, and are finally narrowed into the highest species of finished structure. Thus were produced, if the scientific hypothesis is correct, many varieties or species: creatures being modified by circumstances for circumstances: heredity and adaptation being the two great agents in influencing the variety of living forms. In the finished structure of most advanced life we still find the same original or rudimentary matter out of which all organisms were fashioned, and with which all are now built. The screws, fastening the parts; the levers, raising them to a higher state; the pulleys, drawing them together; the joints, knitting several limbs into one body; even these are constructed on common patterns. This unity in the diverse operations of underlying energy, is a sparkle of the great truth that rules the universe: for example, the hydrogen atoms in the sun and planets vibrating in unison with those on our planet, are like two tuningforks set at concert pitch; and, awaking human response, we say-" The mighty synthesis is proof that God is One." Such reflections are the flowers of our mind, rendering life, present and future, fragrant and useful.

Further development. From inorganic world-elements arise all organisms, and every process of initial life is the prophecy of an advanced life. A germ of life, even before it is large enough to be seen, contains in itself a special endowment-the invisible constructive potentiality of every organ. The first steps of life are in a path common to all, but quickly become special; and every living creature, by way of its own, arrives at a peculiar destination. In plants

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we have production and reproduction; in animals, selfperception, self-control, motion; in man, self-consciousness, will, moral power; the whole wrought by a deep and farreaching energy which science, the shadow of Divine knowledge, likens to the oscillations of a magnetic needle, moved by unseen influences from within and without, that our soul may have a door into the infinite beauty.

The bringing forth of kind after its kind, that process by means of which new individuals are produced, and perpetuation of the species is ensured, presents many marvels. Some of the lowest and smallest animals are of both sexes-hermaphrodite. Others are non-sexual, and the young are produced by gemmation or fission.

Hermaphrodites are double-sexed individuals. Many plants, garden-snails, leeches, earth-worms, various other worms, are of this order.

Gemmation (gemma, a bud) is the production of young by a bud or buds, usually on the outside, but sometimes on the inside of an animal. Thus new life is formed, which may either be completely separated from the parent, or remain connected with it, to form a stock or colony.

Fission (findo, I cleave) is the production of new beings. by the cleavage or division of a primitive zoöid into two or more parts. This fission, occurring frequently, reproduces by tolerably rapid multiplication. An internal fission, or swarming, causes the death of the parent, and produces a vastly multiplied offspring.

In high life, and in the Vertebrata, reproduction is always sexual, and the sexes are in different individuals. Most are oviparous, producing eggs from which the young are developed; but the highest vertebrates bring forth their young alive. Every Divine influence tends to finished perfection of the whole by a mounting heavenward.

Until recent times it was thought that in every species the successive generations were alike-this is called homogenesis. It is now proved that in many plants, and in numerous animals, successive generations are not alike-this is called heterogenesis. The progeny, differing from the parents, produce others, like themselves, or like their parents, or like neither; but eventually the original form reappears. There is no scientific explanation: we can only ascertain the varying order as seen in different creatures. Unmeasured

depths and spaces, lower than the stars and the unknown heavens, make our whole life a pathway to wisdom.

In all cases of sexual production, there is reason to think that, even among the lowest Protozoa, a fusion of two individualities is the process from which results the germ of a new series of individuals. In humblest forms, which have no differentiation of sexes, the union is not of sperm-cells and germ-cells of the same individual, but union between those of different individuals for fresh and better growth.

The power is mysterious, and the more so that the cells, or cradles of life, are not greatly specialised in mechanism, rather seem unspecialised; yet, if there is no special arrangement to secure peculiar conditions of existence for different modes of multiplication, it is certain that invisible arrangements do continually establish themselves. No visible mechanical property explains the profound distinction between the male and female reproductive elements; but in the union of these begins, at once, or on the arrival of favourable conditions, a new series of developmental changes; a process of cell-mutiplication is set up, and the resulting cells aggregate into the rudiment of a new organism. The force by which two adjacent atoms attract or repel each other, their mode of exercise and law of variation, we have not yet enough thought and speech to know and speak. The essence and origin of life lead to Him from whom all life has sprung, according to the patristic interpretation—o yéyovev ἐν αὐτῳ ζωὴ ἦν (John i. 3, 4). "In Him was life, and the

life was the light of men.'

Summarise the principal facts as to the succession of life on the earth.

The creation of marine animals was first, and the first living creature that we know of is the Eozoön. It is probable that primal life existed when the waters were very warm. The coral luxuriates in the equatorial temperature of 86° and more. Infusoria and Crustacea flourish in warm springs, and the life of a germ cannot be destroyed by boiling. "The waters swarmed a swarm," not that the causality was in the waters, but in the creative energy or word—“ Let the waters bring forth abundantly the moving creature that hath life (es sollen wimmeln die Wasser vom Gewimmel)." This life is and has been so abundant that some of the earliest limestones of the globe teem with evidence of former minute

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organisms. This dawn of life was by a long slow process; sponges, corals, crinoids, trilobites, sea-worms, lingulæ, with many other creatures representing five of the great subdivisions of animals-Protozoa, Coelenterata, Annuloida, Annulosa, Mollusca-are found in the very old rocks.

These old rocks have rain indentations, ripple-marks, shrinkage cracks, which prove that the actions of rain, of tide, of sun, and the distribution of light, heat, moisture, were much the same as now. "Were there no land animals to prowl along the low tidal flats in search of food? Were there no herbs nor trees to drink in the rains and flourish in the sunshine? If there were, no bone nor footprint on the shore, no drifted leaf nor branch, has yet revealed their existence to the eyes of geologists." We may, however, be sure that the creative process was not stayed on the land for full development of life in the sea, but that birds and animals lived much earlier than the earliest known fossils indicate. "It is even possible that in a warm and humid condition of the atmosphere . . . when dense 'mists ascended from the earth and watered the whole surface of the ground,' vegetation may have attained to a profusion and grandeur unequalled in the periods whose flora is known

In the Upper Silurian period we find fishes-not of large size, nor abundant-of two separate types. Ganoids, represented at the present day by sturgeons, the gar-pikes of North America, and a few other less familiar forms; Placoids, or shark-like fishes. These two groups are both distinct and highly organised. Ordinary bony fishes were not introduced until comparatively recent time. In the Devonian era was a vast increase, and it became pre-eminently the age of fishes. New lands were upheaved, with extended muddy and sandy flats around them; shoals of fishes, some very remarkable, swarmed in shallow seas and estuaries. Among the most ancient and curious, appearing also in the Upper Silurian, are the Pteraspis, a tribe of mailed fishes, akin to the Cephalaspis, or buckle-head; its broad flat head being rounded in front, and prolonged at the sides into two great spines. Another group of small fishes, represented by the Pterichthys, had two strong bony fins at the sides, which served for "The Story of the Earth and Man," p. 32: J. W. Dawson, LL.D. 2 Ibid. p. 32.

swimming, for defence, for creeping on and shovelling up the mud at the bottom of the sea. There were great fishes with strong cutting double-rowed teeth; with wrinkle-scale, bone-scale, and star-scale; and the huge Dinicthys, having a head more than three feet long and eighteen inches broad, two long sabre-shaped tusks, each a foot long, and a body about thirty feet in length. The Carboniferous fish were numerous-great Ganoids, with sharp bony scales and sharpedged or conical teeth, haunted the creeks and ponds of the coral swamps. Multitudes of sharks, with sharp-edged trenchant teeth; and one species allied to the existing Port Jackson sharks, their mouths paved with flat teeth for crushing shells, sought prey near shell-banks and coral-reefs. The broad-snouted, plate-covered, mud-burrowing crustaceans, the trilobites, are lost in this period. In the Cretaceous period are found the first examples of the great group of Bony Fishes, or Teleosteans, comprising the great majority of forms now existing. The main forms of fishes characterising the Eocene are like those which predominate in existing seas. Those of the Miocene were abundant, and some of the species attained gigantic dimensions.

The amphibious part of creation is the link which joins land animals and fish through the reptiles; and it is difficult to classify some aquatic forms either as amphibia or as fish. There are fish which have the habit of leaving the water for a forage on land. Let their fins be lengthened and moderately altered in shape, the tail modified, and we shall have some of our amphibious animals almost to the life.

In the Carboniferous formation the Amphibia were well developed, and Labyrinthodonts, with exquisite teeth, and the Archegosaura, with large heads, short necks, feeble limbs, and strong tails for swimming, were common. They were of higher order than fish, in possessing lungs and feet. Small vertebrates were in the coal forests named Dendrerpeton and Hylonomus, very reptilian in some points, and probably amphibia in their true nature. Imagine a little animal, six or seven inches long, with small short head, not so flat as those of most lizards, but with a raised forehead, giving it an aspect of some intelligence. Its general form is that of a lizard, but with the hind feet somewhat large, to aid it in leaping and standing erect, and long flexible toes.