The Law of Heredity

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: and mental activities of animals. We do not understand the machinery, but we find that it is there, and we can interrupt its work by obstructing or injuring it. Our wonder is not a feeling of mystery, a sense that the phenomena transcend knowledge; it is due to a perception of the amount of knowledge required. We regard an adult animal with feelings similar to those with which an intelligent savage might regard a telephone or a steamboat;. A dog, with all the powers and faculties which enable him to fill his place as man's companion, is a wonder almost beyond our powers of expression; but we find inhia body the machinery of muscles and veins, digestive, respiratory, and circulatory organs, eyes, ears, etc., which adapts him to his place; and study has taught us enough about the action of this machinery to assure us that greater knowledge would show us, in the structure of the dog, an explanation of all that fits the dog for his life; an explanation as satisfactory as that which a savage might reach, in the case of the steamboat, by studying its anatomy. Let our savage find, however, while studying an iron steamboat that small masses of iron, without structure, so far as the means at his command allow him to examine and decide, are from time to time broken off and thrown overboard, and that each of these contains in itself the power to build up all the machinery and appliances of a perfect steamboat. The wonderful tiling now is not the adaptation of wonderful machinery to produce wonderful results, but the production of wonderful results without any discoverable mechanism; and this is, in outline, the problem which is brought before the mind of the naturalist by the word heredity. Every one knows that each dog exists at some timeas an egg, and the microscope shows iti thi...