Page:Popular Science Monthly Volume 16.djvu/291

Rh  constituting, indeed, one of the great merits of an accomplished colorist. Concerning this matter of contrast Ruskin well remarks: "Every hue throughout your work is altered by every touch that you add in other places; so that what was warm a minute ago becomes cold when you have put a hotter color in another place." The so-called laws of contrast simply point out the nature of these subtile changes. The merit of a colorist is not that he formally follows these laws, but that consciously or unconsciously he is so completely permeated with them in all their varied applications, that they have become a part of himself, enabling him to apply them to complicated cases with a delicate certainty which often appears magical. We are surprised that the critic who assumes to know so much about artists should ask the question, "Ought the artist to regard the laws of contrast?" Established laws can never be disregarded with impunity by any class of men; they are self-executing.

 

is the first volume of what, in the end, is to be a full botanical course of study. Part II., by Professor Goodale, will treat of physiological botany. Part III., by Professor Harlow, will be an introduction to cryptogamic botany; and Part IV., which Professor Gray hopes to accomplish himself, will contain a sketch of the natural orders of phænogamous plants, and of their special morphology, classification, distribution, products, etc.

The title-page of this important installment of the sixth edition will be made more intelligible to the general reader by the following extract from its introduction: "Structural botany comprehends all inquiries into the parts and the organic composition of vegetables. This is termed organography when it considers the organs or obvious parts of which plants are made up, and morphology when the study proceeds on the idea of type." By taxonomy is meant "the principles of classification," and by phytography "the rules and methods of describing plants." In the opening paragraph of Chapter I. it is further explained that morphology, the doctrine of forms, as the name denotes, is used in natural history in nearly the same sense as the older term comparative anatomy. If it were concerned merely with the description and classification of shapes and modifications, it would amount to little more than glossology and organography. But it deals with these from a peculiar point of view, and under the idea of unity of plan or type.

The first edition of Gray's "Text-Book of Botany" was published in 1842, in one moderate-sized octavo volume. The four subsequent editions were each a little enlarged from its predecessor; but, until now, one volume has sufficed for the treatment of the entire field of botanical science. When it appeared, botany was not generally studied in our schools. The analysis of flowers by the Linnæan system was fashionable in girls' seminaries, where there was a pretense of studying plants themselves; but it resulted in the merest pedantry. The system of classification was artificial; it did not appeal to the rational faculties, as did natural philosophy and chemistry; and sensible boys and girls repudiated the subject. To give it rank, it had to be placed on a new basis and Gray's "Test-Book" accomplished this by the masterly way in which he presented the life-history of plants. The structure and development of cells was clearly set forth, the natural system of classification was adopted, and the study became both rational and attractive.

But other changes besides increase of size have taken place in this text-book. In