Page:Popular Science Monthly Volume 55.djvu/579

Rh original, including even typographical errors, excepting only the style of type. Of the original edition only eight copies are known to exist, so that the republication was desirable to preserve the book, as well as for the facilitation of reference, and of this only two hundred and fifty numbered copies are printed for the market.

Mr. Douglas Houghton Campbell has endeavored, in his Lectures on the Evolution of Plants, to present in as untechnical a manner as seemed feasible the more striking facts bearing upon the evolution of plant forms, believing that it will fill an existing want among English text-books. The substance of the work was given originally in the form of lectures to classes in Leland Stanford Junior University. After an introduction, in which a few fundamental principles are presented, elementary structures are defined, and accepted classification is mentioned, the conditions of plant life are treated of as relating to food substances, water, life, division of labor, and movements, of which all plants exhibit more or less marked ones, that may be spontaneous. While in the simple unicellular plants all the functions are performed by a single cell, a gradual division of labor takes place as we go up, first in a separation of the vegetative and reproductive cells, and later a further specialization of both vegetative and reproductive functions, culminating in the seed plant. This course is described as exemplified in the simplest forms of life, algæ, fungi, mosses and liverworts, ferns, and seed plants of the different classes. The study of the geological relations, fragmentary as their teachings are, has yielded most important evidence for tracing the succession of plant forms. Observation of geographical distribution casts much light on the subject. The relations of animals and plants have an important bearing. The influence of the environment embraces many factors, and is often shown in conspicuous features of form and structure adapting plants to certain sorts of conditions and enabling them to resist others. Plants have thus succeeded in adapting themselves to almost every environment.

Prof. Augustus de Morgan's book On the Study and Difficulties of Mathematics, though originally published more than sixty years ago, is still fresh and suggestive and full of matter valuable alike to students and teachers, and possesses qualities of clearness of reasoning and intelligibility from which many mathematical treatises are unfortunately free. Its purpose is to notice particularly several important points in the principles of algebra and geometry which have not obtained their due importance in elementary works in those sciences. Metaphysical points are avoided, and the method of explaining by reference to some particular problem, with hints as to more general adaptation, is adopted. Among the points taken up and classified are the nature and objects of mathematics, arithmetical and algebraic notation, rules and principles, equations, the negative sign, roots and logarithms, geometrical subjects, and application of algebra to measurements. The editor of the present edition, Mr. Thomas J. McCormack, has corrected the errata of the old edition and incorporated such changes as the progress of time and mathematical literature have made seem proper. An excellent portrait of De Morgan is given.

The purpose of Carpenter's Geographical Reader, North America (American Book Company), is to give its readers a living knowledge of some of the wonders of the country and continent in which they live. They are taken by the author, Mr. Frank G. Carpenter, on a personally conducted tour through the most characteristic parts of the American continent, studying the most interesting features of life and work among the people, learning how they are governed, and how they make their living. Much information is also given concerning the natural resources and the physical features of the countries visited.

The Japan-American Commercial Journal is a monthly periodical started with the beginning of the year, with