To return to the _role_ played by the germ in the question of heredity, we repeat that the physical germ, of itself alone, explains only a portion of man; it throws light on the physical side of heredity, but leaves in as great darkness as ever the problem of intellectual and moral faculty. If it represented the whole man, one would expect to find in any individual the qualities manifested in his progenitors or parents--never any other; these qualities could not exceed the amount possessed by the parents, whereas we find criminals from birth in the most respectable families and saints born to parents who are the very scum of society. You may come across twins, _i.e._, beings born from the same germs, under the same conditions of time and environment, one of whom is an angel and the other a demon, though their physical forms closely resemble each other. Child prodigies are sufficiently numerous to frequently trouble the thinker with the problem of heredity. Whence came that irresistible impulse towards poetry in Ovid which showed itself from his earliest youth and in the end overcame the vigorous opposition of his parents? Pascal in his youth met with keen opposition from his parents, who forbade him to think of mathematics and geometry. He besought his father to tell him, at all events, "what was that science of which he was forbidden to think, and what it treated of." The answer was given to him that "it is the method of making correct figures and finding out the proportions they bear to each other." With nothing more than this information and the aid of reflection, he discovered for himself the first thirty-two propositions of Euclid by means of "circles and lines" traced in secret. Mozart, at the age of three, learnt the clavecin by watching his sister play; a year afterwards he composed admirably, at the age of seven he played the violin at first sight without having had any teacher, and proved himself a composer of genius before he reached his twelfth birthday. Pepito Ariola, the little Spaniard, was only three years of age when, about ten years ago, he filled with astonishment the Court of Madrid by his wonderful playing on the piano. In the lineage of these prodigies has there been found a single ancestor capable of explaining these faculties, as astonishing as they are premature? If to the absence of a cause in their progenitors is added the fact that genius is not hereditary, that Mozarts, Beethovens, and Dantes have left no children stamped from birth as prodigies of genius, we shall be forced to the conclusion that, within the limits it has taken up, materialism is unable to explain heredity. A few more words must be said on physical heredity to explain why moral qualities in men of average development are often on a par with the same in their parents.