THE POPULAR SCIENCE MONTHLY.
laws, than in the evolution of a summer's shower, through the laws discovered by the meteorologist, who looks back through myriads of ages to the causes that led to the distribution of mountain-chains, ocean-currents, and trade-winds, which combine to produce the necessary conditions resulting in that shower.
"Indeed, to the student of Nature, the evolution theory in biology, with the nebular hypothesis, and the grand law in physics of the correlation of forces, all independent, and revealing to us the mode in which the Creator of the universe works in the world of matter, together form an immeasurably grander conception of the order of creation and its ordainer than was possible for us to form before these laws were discovered and put to practical use."
Again he says:
"Thus the ovipositor of the bee has a history, and is not apparently a special creation, but a structure gradually developed to subserve the use of a defensive organ. So the organs of special sense in insects are, in most cases, simply altered hairs. The hairs themselves are modified epithelial cells. The eyes of insects, simple and compound, are at first simply epithelial cells, modified for a special purpose; and even the egg is but a modified epithelial cell attached to the walls of the ovary, which in turn is morphologically but a gland. Thus Nature deals in simples, and with her units of structure elaborates as her crowning work a temple in which the mind of man, formed in the image of God, may dwell. Her results are not the less marvelous because we are beginning to dimly trace the process by which they arise. It should not lessen our awe and reverence for Deity if, with minds made to adore, we also essay to trace the movements of his hand in the origin of the forms of life.
"Some writers of the evolution school are strenuous in the belief that the evolution hypothesis overthrows the idea of archetypes and plans of structure. But a true genealogy of animals and plants represents a natural system, and the types of animals, be they four, as Cuvier taught, or five, or more, are recognized by naturalists through the study of dry, hard, anatomical facts. Accepting, then, the type of articulates as founded in Nature from the similar modes of development and points of structure perceived between the worms and the crustacea on the one hand, and the worms and insects on the other, have we not a strong genetic bond uniting these three great groups into one grand sub-kingdom, and can we not in imagination perceive the successive steps by which the Creator, acting through the laws of evolution, has built up the great articulate division of the animal kingdom?"
Proportions of Pins used in Bridges. By Charles Bender, C. E. No. IV., Van Nostrand Science Series, 52 pages. Price, 50 cents.
This is a very small book, but it would certainly be wrong to measure its importance by its dimensions. In science, we are often told that there is no great and no small, by which it is meant that the interest and value of things in Nature are not dependent upon magnitude. It is desirable, as we all feel at times, that bridges should be well constructed, and, as their parts are held together by pins, all who travel are interested that these pins should be in proper proportions. Thanks to Bender for determining what these proportions are, and to Van Nostrand for diffusing a knowledge of them. We bear our testimony to the importance of the research, and the value of the publication, but we regret to say that we cannot recommend this monograph for popular reading, as it is brimful of mathematics.
A Treatise on Analytical Geometry. By William G. Peck, LL. D., Professor of Mathematics and Astronomy in Columbia College, and of Mechanics in the School of Mines. 212 pages. A. S. Barnes & Co.
Prof. Peck has prepared this treatise for the use of his own classes in Columbia College and the School of Mines. His object has been to present the subject in a narrower compass than is done in the usual voluminous works that are employed as text-books in the mathematical departments of the higher institutions. The author puts forward no claims to originality of method, and states that the gen-