I must at the outset remark that among the many sciences that are occupied with the study of the living world there is no one that may properly lay exclusive claim to the name of Biology. The word does not, in fact, denote any particular science but is a generic term applied to a large group of biological sciences all of which alike are concerned with the phenomena of life. To present in a single address, even in rudimentary outline, the specific results of these sciences is obviously an impossible task, and one that I have no intention of attempting. I shall offer no more than a kind of preface or introduction to those who will speak after me on the biological sciences of physiology, botany and zoology; and I shall confine it to what seem to me the most essential and characteristic of the general problems towards which all lines of biological inquiry must sooner or later converge.