Page:Popular Science Monthly Volume 49.djvu/145

Rh the rocks in which they are found. The text is illustrated with forty outs.

The inscription on the back of a volume before us is a most unfortunate one, for if the student does not take the trouble to look between the covers he is led to believe that the book is an extensive monograph on Peripatus, with forms closely related to this extraordinary animal. If he passes it in consequence of this misleading title, he will have missed an exceedingly condensed and clear account of the external features, habits, and anatomy of Peripatus by Mr. Sedgwick, filling twenty-six pages; a most valuable chapter of fifty pages on the Myriapoda, by F. G. Sinclair; and another chapter on the orders Aptera, Orthoptera, Neuroptera, and Hymenoptera, by David Sharp, of five hundred pages! As the other orders of Insecta are to be dealt with in Volume VI of this series, one wonders what the lettering on the back of Volume VI will be—possibly Peripatus, etc., by Sedgwick, see Volume V, or, as it will begin with the Coleoptera, some low and aberrant form will be selected, and on the back the comprehensive title Stylops, etc., will stand for the great orders Coleoptera, Lepidoptera, Diptera, and Hemiptera! With this criticism, we can only say that the book upholds the reputation already established for the series. The illustrations are many and beautiful, the descriptions and grouping of the material clear, and the work an indispensable one to the general student of this great class of animals.

In two text-books on zoölogy recently received provision is made for two modes of instruction. In the one the scientific method of acquiring knowledge of natural history—through field study and laboratory work—is consistently carried out. A comparatively small number of typical forms (thirty-two), ranging from the amœba to the rabbit, are chosen for study, all being such as may be easily obtained at inland points as well as near the sea. The chapter on insects shows the method of the book. It begins with directions for collecting specimens. The sulphur butterfly is the first species to be studied, and enough of its characteristics are given to enable the student to recognize it. He is directed to collect specimens for study, and while collecting to observe such things as the kind of flowers on which they are found feeding, whether they feed on the wing or not, the organ used in obtaining food, its position when in use and when not in use, its shape and length. Other observations are to be made on a specimen liberated indoors before a closed window. The study is continued with dead specimens. At the end of the chapter on insects is a general account of the life process in this group of creatures. This is followed by a review exercise which involves considerable observation, and after this a lesson in classification is given. An appendix contains lists of books and reagents, full directions for obtaining and preparing material for study, a glossary, etc. There are one or more illustrations for each species studied.

Recognizing the fact that in many large schools, especially in cities, it is impossible to secure provision for either laboratory work or field excursions by classes, Miss Burnet has aimed to provide as good a substitute as may be in book form. Not being limited to animals everywhere procurable, she ranges through the whole kingdom from amœba to man, and gives brief descriptions of a large number of species, including many salt-water dwellers. Independent collecting by the pupil is encouraged to supply the deficiencies of text-book study, directions for taking specimens and preparing them for the cabinet being given in some detail. There are one hundred and ninety-seven illustrations.

The author of this book, to whom the original structure of the universe has long been a favorite subject of study, has here presented a modified form of the nebular theory of Laplace, based on certain calculations and new ideas of his own. As a starting point, he suggests the possibility of a more attenuated form of matter than we