THE CRAYFISH: AN INTRODUCTION TO THE STUDY OF ZOOLOGY.
CHAPTER I. TIIE NATURAL HISTORY OF THE COMMON CRAYFISH
(Astacus Jluviatilis.') Many
persons
seem to believe that wliat is termed
Science is of a widely different nature from ordinary knowledge, and that the methods by which scientific truths are ascertained involve mental operations of a recondite and mysterious nature, comprehensible only by the initiated, and as distinct in their character as in their subject matter, from the processes by which we discriminate between fact and fancy in ordinary life. But any one who looks into the matter attentively will soon perceive that there is no solid foundation for the belief that the realm of science is thus shut off from that of common sense ; or that the mode of investigation which yields such wonderful results to the scientific inves¬ tigator, is different in kind from that which is employed
