“From the Egg to the—?

South Canterbury Times, Issue 7070, 16 February 1893, Page 1

“From the Egg to the—?

Which came first - hen or egg ? This question, with which the exulting defender of the theory of special creation was wont to cap hie arguments, has been answered within the last half century or more. The Greeks went in quest of the answer 2000 years ago ; but it was reserved for the present century to solve the riddle. In 1838 Schleiden traced the plant embryo to a single nucleus enclosing cell, and in 1839 Schwann traced the animal embryo to a like primordial structure. All life comes from egg or cell. Ihe cell is the fundamental structure of living things, the unit of which every plant and animal is built up. The lowest organism consist only of one cell j the higher are made up of many ceils, which increase in com* plexity and diversity of form adapted to the various work which they have to do, and which become modified into tissues, with re suiting unlikeneas in parts or organs. Therefore the “ infinite variety " of living things is due to change in cell-structure and cellarrangement, and every organism is propagated in one way of another by cells, by their clustering together, or their self division, or their germination. The egg-cell, or ovum, is the starting-point of the embryo, and although from the infinite, the ultra-microscopic minuteness, of the phenomena, and the difficulty attaching to their examination in the ovary, but little is known about the earliest processes of development, the identity of structure of organisms soon becomes apparent. The vertebrata or baek-boned animals exhibit persistent likeness up to a certain stage, and thus disclosing a common ancestral type. In other words, the embryo, as it develops, epitomises tbe series of changes through which the ancestral forms passed in their ascent from simple to complex organisms. For example, the embryo of man has at a certain stage gill-like slits on each side of the nock like a fish ; those give place to a membrane like that which supersedes gills in the developement of birds and reptiles ; tbe heart is at first a simple and pulsating chamber like that in worms ; tbe backbone is prolonged into a movable tail ; the great toe is extended, or opposable ; like our thumbs and like the toes of apes; tbe body, three months before birth, is covered all over with hair, except on tbe palms and soles. Other details might be added, all evidencing that the egg from which man springs—a structure only l-250ths of an inch in diameter, compresses into a few weeks tbe results of millions one of years, and sets before us the history of his development from fish-like and reptilian forms, and of his more immediate descent from a hairy, tailed quadruped of arboreal habits. Carl von Baer, to whom the discovery of tbe mammalian egg in the ovary is due, gives the following striking account of these resemblances :- In my possession are two little embrosy in spirit, whose names I have omitted to attach, and at present lam quite unable to say to what class they belong. They may be lizards, or small birds, or very young mammalia, so complete is the similarity in the mode of formation of tbe head and trunk in these animals. The extremities, however' are still absent in these embrosy. But even if they had existed in the earliest stage of their development we should learn nothing, for the feet of lizards and mammals, tbe wings and feet of birds, no less than the | hands and feet of man, all arise from the I same fundamental form. I