A COURSE OF ELEMENTARY INSTRUCTION IN PRACTICAL BIOLOGY BY T. H. HUXLEY, LL.D., SEC. R.S., ASSISTED BY H. N. MARTIN, B.A., M.B., D.Sc. NEW EDITION. London: MACMILLAN AND CO. [The Right of Translation is reserved.] KD 60451 3008. 93 HARVARD COLLEGE LIBRARY G.. OF LLOWED WOW.HILIGION SARGENT Cambridge: PRINTED BY C. J. CLAY, M.A. & SON, AT THE UNIVERSITY PRESS. G PREFACE. VERY Soon after I began to teach Natural History, or what we now call Biology, at the Royal School of Mines, some twenty years ago, I arrived at the conviction that the study of living bodies is really one discipline, which is divided into Zoology and Botany simply as a matter of convenience; and that the scientific Zoologist should no more be ignorant of the fundamental phenomena of vegetable life, than the scientific Botanist of those of animal existence. Moreover, it was obvious that the road to a sound and thorough knowledge of Zoology and Botany lay through Morphology and Physiology; and that, as in the case of all other physical sciences, so in these, sound and thorough knowledge was only to be obtained by practical work in the laboratory. |