��POPULAR SCIENCE MONTHLY.
��good to take up at any time of the day and to read steadily or in five to fifteen minute intervals. Six of the papera first appeared in the North American Review (Roberts Brothers, $1.50).
The second volume of The Cambridge Natural History (Macmillan, $3.50) contains a connected and comprehensive history of the flatworms and mesozoa, nemertines, threadworms and sagitta, rotifers, polychaet worms, earthworms and leeches, gephyrea and phoronis,. and polyzoa. These various subdivisions are dealt with by special stu- dents and zoologists. The chapters on poly- chaet worms, gephyrea and phoronis, and polyzoa are particularly acceptable as bring- ing together much information that has here- tofore been locked up in special memoirs. In the chapter on rotifera, Prof. Hartog pre- pents for the first time his views on the zoo- logical affinities of the group. He says : " I have been induced to take a view of the structure of the rotifers that brings it into close relationship with the lower platyhel- minthes and with the more primitive larva of the nemertines termed pilidium." He there- fore changes the orientation of the rotifer, and places it, like the cuttlefish, mouth down- ward. For anterior and posterior he substi- tutes oral and apical ; for dorsal and venti-al he uses anterior and posterior. As in the volume on insecta, the name of the author of the first chapter only stands conspicuously on the cover. The volume and the whole series, in fact, is in a way so encyclopedic in its character that it seems as much out of place to have an author's name on the cover as it would be to see a single author's name on an encyclopicdia. The volume is an indis- pensable adjunct to the library of a natural- ist. The beautiful illustrations, the matter, well up to the latest researches on the sub- ject, and the fact that specialists in each de- partment have contributed to its material, bringing in their own original work, make the series unique and invaluable.
The United States Weather Bureau has issued a folio pamphlet on Surface Currents of the Great La/;f.s, deduced from the courses taken by floating bottles put into the waters of the lakes in 1892, 1893, and 1894. Of the five thousand bottles set afloat by the Bureau, six hundred and seventy two had
��been recovered up to the preparation of this report. The text is accompanied by a chart of each lake, showing the courses taken by the bottles each season, and the movements of the waters which these courses indicate.
The Report of the Commissioner of Edu- cation for the Year 1893-94 makes two vol- umes of the familiar form containing over a thousand pages each. The usual statistics are accompanied by a large number of essays on educational topics. The reports of the " Committee of Fifteen " on training of teach- ers, on correlation of studies, and on city school systems, which have aroused wide- spread interest, are here printed ; Rev. A. D. Mayo contributes a history of public schools during the colonial and revolutionary period;". A digest of school laws in the several States and of sanitary laws affecting schools occu- pies about three hundred pages. Other fea- tures are A Preliminary List of American Learned and Educational Societies, giving the officers, objects, and publications of each, and Some Recent Educational Bibliographies. There was an increase of over four hundred thousand pupils in the public schools of the country during the year, against an average of less than three hundred thousand for the preceding ten years.
A useful contribution to the current dis- cussion of the money question is afforded in No. 74 of the Old South Leaflets, Hamilton's Report an the Coinage. All the important phases of the currency problem are dis- cussed calmly and thoroughly in this mas- terly report of the first Secrefciry of the Treasury, and it is highly instructive to see how an able financier, unatfected by any of the prejudices of the present day, looked at matters that are now in hot dispute. The report makes a pamphlet of thirty-two pages. (Directors of the Old South Work, Boston, 5 cents a copy, $3 a hundred.)
Describing his book, Tite Perfect Whole (Ellis, $1.50), in its preface, Horatio W. Dresser says : " Thus, broadly defined, the purpose of this book is threefold psycho- logical, metaphysical, and practical. As a psychological analysis, it is especially con- cerned with the higher or spiritual nature of man. As a philosophical discussion, it aims to develop a generally sound view of reality by a consideration of materialism, agnosticism,