Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: CHAPTER III. OUR NATURAL INHERITANCE. §1. The Three Fates.—§2. The Elements of Our In heritance.—§ 3. Fundamental Facts of Heredity.—§ 4. Recent Advances in the Study of Heredity.—§ 5. Different Modes of Inheritance.—§ 6. Statistical Study of Heredity.—§ 7. Inheritance and Disease. § 1. The Three Fates. As far as Biology is concerned there are three determining factors in life. First and foremost there is our flesh and blood relation to parents and ancestors (Heredity); second, there are all sorts of surrounding influences (Environment), along with which may be included opportunities; and third, there are our habits (Function), both positive and negative, doing and not- doing,—for sluggishness moulds the body as surely as strenuous exercise. As all the three factors—we may say Three Fates—are powerful and always operative, it is not very urgent to argue about the order of their importance. Men cannot make bricks without clay— that is, the natural inheritance. Neither can they make them without heat—that is, the environmental factor. A living creature cannot realise its initial self,i.e. its inheritance, without activity or exercise, without food, or without the stimulus of appropriate surroundings, but the way in which the creature uses the influences that play upon it, the way in which it girds up its loins to work or lets itself go in play, is in part determined by what it owes to parents and ancestors. In part, not wholly; and that for two reasons:—first, because peculiarities in the circumstances count for something in themselves, being often provocative to effort and often deadening in their dullness; and, second, because each new creature, while owing everything to the past, has in some measure an individuality of its own and thus an element of unpredictability. He...