CHAPTER VIII. The Parents. O what extent is a man responsible to his ancestry and parentage for his character and career? Like all other organized composite units of the world man is a product of natural forces. There is nothing particularly mysterious in his making if we trace all the forces that enter into it to their very beginning. It is true, man is "fearfully and wonderfully made." Science in this respect has corroborated the declaration of religion. But it requires no inspiration to reveal this truth when Nature herself affords us such ample intimation of its existence. We say that man is fearfully and wonderfully made, but we shall not fully realize what this means till we first understand how wonderfully and fearfully made is the egg from which he is evolved. For the primal human cell, that little dot of mysterious matter, in which inhere all the possibilities of buman individuality and racial history, contains within its microscopic pages the full prophetic forestallment of the man to be. It is true that the tree is in the seed, the oak in the acorn, in a strictly literal sense. For while indeed the tree is not fulldeveloped in miniature in the seed, it is also true that the full capacity of the tree is already potential in the seed undeveloped. In short, what the tree is to be is forewritten in the seed. Yea, more than this, what the seed is to be is forewritten in the primal protoplasmic cytode, from which the cell and seed, the tissue and membrane, the leaf and flower, the tree and fruit, shall finally evolve. Two tremendously prophetic and startling facts greet us on the threshold of this study. The first marvel is that the germ-plasm, the primal life substance from which all forms of organic life proceed, is ever and absolutely similar and indistinguishable. No microscope can penetrate the mysterious depths of the speck of protoplasm and foretell its history. None can see within the mysterious depths of the cell what may be its prophecy, whose fulfilment shall mean a fish, or bird, or reptile or a biped. Not till the cell begins to divide itself into a multitude of cells and at length undertakes to build up an organism can we learn the tendency of its development. Here in the primal womb of undifferentiated life lies the impenetrable mystery of the individual life. But the second and still more startling marvel that confronts us is that the germ-plasm from which each distinctive, differentiated and individual life proceeds, which in its own time shall expire and disappear, is not itself subject to death, but has ever persisted since the first slimy bit of living substance emerged from the cosmic breast. The life substance is found to consist of two elementary stages. The first stage is homogeneous, and as yet wholly indistinguishable. It exists without a nucleated centre. It is all alike. This is designated as the cyto-plasm. Had it never developed beyond this stage there would have been no such thing as individualized organic life on the globe. But it assumes a second stage, that is, the stage of the nucleus. When the nucleus is aggregated within the cytode, then comes the beginning of individualized life. Some mysterious force operates within the differentiating nucleus that causes the ultimate forms of organic expression to be diversified. "It is under the influence of the nucleus, that the cell-substance re-develops into the full type of the species. In adopting the view that the nucleus is the factor, which determines the specific nature of the cell, we stand on a firm foundation upon which to build with security" (Weismann). But so marvellous are the workings of Nature that we can almost trace the evolution of the nucleus from the cyto-plasm, stage by stage. The nucleus of Weismann is not the ultimate differentiable division of the first form of the life substance. The nucleus itself reveals another centre, the nucleolus, and this again reveals a source from which it sprung, the nucleololus. But the possibilities of the microscope are not exhausted, and who shall say that we shall not yet discover the very point at which the plasm begins its differentiation into germinal nucleated expression. But what bearing does this have on the art of the making of a man? Much in every way. For we learn that within the primal plasm itself inhere the physical tendencies and potentialities of the entire race, in microscopic and miniature prophecy, while within the nucleus lie the profound forces that tend to separate the individual life from the composite life-tendencies of the race. So that when a plant, or an animal or a human being arrives at potential expression, in the procreation of the vital germ from the sexualized cells, it already contains within its infinitesimal form the impress of the entire history of the race, and the additional distinctive impress of a specialized line of descent which culminates in its parental source. THE WORKING OF THE LAW OF HEREDITY. "Heredity is brought about by the transference from one generation to another of a substance with a definite chemical, and above all, molecular constitution. I have called this substance, 'germ plasm,' and have assumed that it possesses a highly complex structure, conferring upon it the power of developing into a complex organism. I have attempted to explain heredity by supposing that in each ontogeny a part of the specific germ-plasm contained in the parent egg-cell is not used up in the construction of the body of the offspring, but is reserved unchanged for the formation of the germ cells of the following generation" (Weismann). By this law we learn how the species of each animal kingdom is generated and differentiated from all the rest, and how when once the species is produced each individual member maintains its distinctive characteristics. Thus, as Darwin reminds us, "Heredity produces an exact copy of the parent in the child. We may feel assured that the inherited effects of the use and disuse of parts will have done much in the same |