Page:Popular Science Monthly Volume 81.djvu/151

Rh made little progress. At the beginning of the last century it was in a backward condition. Improvements in the microscope and in the knowledge of its use, the studies of such men as Amici of Modena, Lister in England, the botanists Hugo von Mohl and Nägeli, of Stokes, Lord Rayleigh and Helmholtz, and the skill of Professor Ernst Abbe, of Jena, who has at his back the celebrated firm of Carl Zeiss, have rendered an exact study of cell life or formation of the tissues of all the processes and conditions of life possible and of value. But if tbe study of geology morphologically has produced men like Lyell, if in botany we have the great names of the Jussieus and De Candolle, in zoology, of Daubenton and Cuvier, more and more clearly has it been seen that nature is after all a unit in her processes. In the new field of astrophysics in which so much use is made of the spectroscope there is hardly a science known which is not employed in its development.

Yet the morphological study of nature alone could not long be satisfying. The progress made in the study of biology, the publication of Darwin's "Origin of Species" and Herbert Spencer's suggestion of the "physiological unit," called attention away from the forms of natural objects, from their study as individuals or collectively, or in relation to each other, from their distribution in various parts of the earth, to the changes wrought in them through the lapse of time, or by water, fire or convulsions of nature, to the processes of their formation or growth. Thus their genesis becomes of even greater interest than their form or their distribution. Indeed even the morphologist feels that his method of interpreting nature would be more satisfactory if he were fully acquainted with the methods which nature employs in the introduction and support of life.

This theory, the second of those we are now considering, is known as the genetic theory—and so called from its dealing with life. This theory assumes that all things are in motion and are developing along many lines, yet after some real order, if not after a fixed and definite plan. The word evolution, so generally used in England to indicate this process, is not universally employed in France or Germany. Herbert Spencer has the credit and the responsibility of introducing the word evolution into English-speaking scientific circles and also for using the word genesis to set forth a purely mechanical conception of the universe.

What we desire to know and seek to know is, How have things come to be, what they are and what is their history in time? Leibniz in his tract "Protogaea," published in 1749 called attention to the part fire and water have had, as indicated by visible proofs of their action, in forming the surface of the earth. He suggested a thorough study of many localities in order that general and satisfactory conclusions might be reached. Kant, influenced as he admits by the theories of Thomas Wright, of Durham, as to the formation of the planetary system,