H. M. STANLEY : pearance of a tree with intertwining branches, rather than of an upright pillar. The genetic classifications of organisms and languages, and all genealogies present this ramifying order. It was a mistake in Cornte to suppose that a linear order could represent an evolution. Owing to the many circumstances, social, political, and religious, which have influenced the appearance of the sciences, in their organised as well as their descriptive stage, a classification according to historic development presents great difficulties. Both Mr. Spencer and Mr. Fiske have very justly insisted on the complexity of influence. We hope, however, that in these days of enthusiastic historical research some one may be found to give to the history of the sciences the attention it deserves, and bring out clearly a genetic classification and the laws of the growth of the sciences. It may not be amiss here to turn aside and consider a law of the growth of the sciences which seems to me of some im- portance, and that is the law of growth from static to dynamic. This has been hinted at by Prof. Joseph Le Conte and others, but has not yet received the discussion which it merits. This is a law of progress, not only in scientific, but also in ordinary and philosophic knowledge. Ordinary observation naturally proceeds from noticing what things are to observing, or more frequently guessing as to, how things have become what they are. Mytho- logies and folk-lore have, to a great extent, grown up in this way. Philosophy in Greece speculated as to how things have be- come what they are, and set forth water, fire, and air as primal elements. In science the ancients were mostly confined to the descriptive stage ; there were no scientific theories of atoms and evolution, only philosophic hypotheses ; and the sciences re- mained for the most part undetached from their mother philo- sophy. After the moderns had caught up the broken thread of past culture, they began to observe for themselves, and descriptive science progressed very rapidly. Great advances were early made in Geography, the static science which treats of the earth as it is ; but geology, the dynamic science of how the earth became what it is, rapidly developed at a much later period. Static Astronomy grew up under the labour of Copernicus, Galileo, and Kepler, but it was reserved for Kant and La Place to propound the nebu- lar theory of the development of celestial bodies and systems. Physics has, within comparatively recent times, received its dy- namic complement in the theory of the convertibility of forces. Mr. Norman Lockyer's recent hypothesis of the convertibility of the elements has in it a gleam of promise that we may yet know the history of the elements. Botany and Zoology, the sciences of plants and animals as being, are now supplemented by Biology, the science of organisms as becoming. Human Psychology was long a simple static science of mind, but Paedagogy, as the science of education, the science of mental growth, and, applied as an art, the art of inducing mental growth, is now fast becoming the
