ical treatise for students and a popular book for readers. Schleiden composed both. The time had passed when the study of living beings should form a separate branch of science, and when those who discarded the dry enumerations of the classifiers would have to fall into the ideal reveries of the "philosophers of nature." It needed to be shown that botany was not the mere dry skeleton which the former would make of it, and that it did not require the tinsel with which the latter assumed to adorn it. In the "Grundzüge der wissenschaftlichen Botanik" ("Elements of Scientific Botany") of Schleiden, the science was for the first time treated entirely according to the inductive method, as physics and chemistry had already been considered; and the different branches of science, till very recently still isolated and almost hostile, were made to interpenetrate and mutually illustrate each other. The book was well adapted to enlarge the scientific horizon, and to inspire youth and develop the spirit of research in them. The reading of the first few pages of the book is sufficient to give this impression of its motive. The dedication to Alexander von Humboldt, unquestionably the man of most universal knowledge of his time, attests the author's desire to connect botany intimately with the other sciences. The capital importance which he rightly attached to method is affirmed by the title which he gave to the second edition of his treatise—"Botany as an Inductive Science." The very first lines of his preface show that he does not intend to deal with a science of words and dreams, but of observation, experiment, and independent thought. "Whoever thinks he can learn botany in this book may as well put it aside at once without reading it, for botany can not be learned from books." In this work, says Dr. Karl Midler, Schleiden expressed for the first time a full comprehension that natural science was essentially a history of development, and expressed it in such a manner as to attract enthusiastic youth to his doctrine while he incurred the hostility of the elders in science. Among the salient features of his theory are the ascription of a leading part in all morphological questions to the study of the development of the organs, and his putting of the cryptogams upon a footing of equality in consideration with phanerogams. Perhaps no innovation in science has been so fruitful as the step which gave the prominent place in study to the first, stages rather than to adult forms, to inferior beings rather than to elevated and complex groups.
One passage in the "Grundzüge" is worthy of especial remark, for the evidence it bears of the completeness of the author's rejection of the sterile categories of the older philosophers, and of his having been endowed with the scientific spirit of later times. "The division of natural objects into organic and inorganic could only have originated at a time when students had only the two extremes to consider. A person comparing a lion with a piece of chalk would, doubtless, say that the difference is evident to all the senses. But let him compare