Page:Popular Science Monthly Volume 30.djvu/431

Rh Sihler, M. D. In this memoir is described a new method of demonstrating the nerve-endings in the muscles of the frog, as well as to bring forth evidence supporting the view that the terminal nerve-fibers are situated on the outside of the sarcolemma, and do not, as taught by most authorities, penetrate this envelope."

"Marine Larvæ and their Relation to Adults," by H. W. Conn, is an interesting memoir on the relations of various large groups of animals, based on the larval stages of these groups. Based on these relations solely, the author would place in the first group Cœlenterata, Polyzoa, and Brachiopoda; in another group the Mollusks and Annelids, and probably the Planariane; while a third group would contain Echinoderms, Balanoglossus, and probably the nemerteans and vertebrates. As the sponges and arthropods show no approach to the pilidium larva, they are not considered. Possibly this novel classification might be completed by uniting these in a fourth group! The volume closes with a paper by William Trelease, entitled "Observations on Several Zoögloeæ and Related Forms." This paper deals with bacteria, micrococcus, and related forms, with determinations of new species.

We may add that these papers are highly technical, and are accompanied with excellent plates.

work has been prepared to meet the wide-spread and growing demand for a treatise on arithmetic adapted to the objective methods of instruction now common in schools. In its preparation the author has kept in view the thought that words are useless in the measure that they fail to call up in the mind vivid images of the things signified; and that, to the learner, the operations of arithmetic are apt to be only manipulations of figures after prescribed models, unless he realizes the fact that they are representatives of processes that may be applied to material objects. Hence the attempt has been made to vitalize the relation of words and things by the aid of the best practicable illustrations at every point; and to bring forward problems, or examples for solution, that should have life in them, or bear some relation to the affairs of everyday life. The work has been adapted, as far as possible, to the needs of those children who are liable to be withdrawn from school before a full course in arithmetic can be completed. Hence, the more useful business applications of elementary principles are made as soon as they are learned. Thus, familiar measures are introduced before reduction is mentioned; federal money before decimals; many practical measurements before mensuration; and questions even in percentage and interest are met with before those subjects are reached in due course. The conditions of these problems are so presented as to be within the easy understanding of the pupil, while their solution requires only such arithmetical operations as he has already learned. The authors also call attention to the simple treatment of the decimal system of notation and the variety of exercises under it; to the multiplicity of short exercises, while longer ones are not wanting; to the directions to the pupil, having in view the formation of right habits of computation; to the suggestions for original problems; to the simple and direct methods of treating the various subjects; and to the rigorous adherence to the inductive methods of instruction.

this pamphlet Mr. Gladstone explains and vindicates the position on the Irish question which he assumed and maintained while he continued in office as the working head of the British Government. The discussion is divided into two parts, with papers under the headings, "History of an Idea" (the Irish idea of home-rule), and "Lessons of the Election." The "Lessons" are for the Liberal party and for Ireland, and relate to the purchase and sale of land, and the conservatism of home-rule. In the conclusion, Ireland is advised to walk to the consummation of her wishes in the path of constitutional and peaceful action, and of steady, free, and full discussion, which has led England and Scotland to triumph.