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Rh in 1896 was guided by the consideration of bringing to the attention of the public geological deposits of great importance, and of choosing such locations as would elucidate as large a number of geological problems as possible. Six counties are described and mapped as geologically important in respect to indurated rocks and superficial deposits, and as being, therefore, of great practical interest to the people of the State. The soils are treated as economically the most important formations. Tests of building stones have been completed and are ready for publication. Attention corresponding to their importance was given to the study of the coal beds. It was incidentally demonstrated that the succession of Pleistocene deposits is more complete and more clearly indicated in Iowa than in any other corresponding area of this continent so far studied. The State Geologist is gratified to represent that the publications of the survey are being more and more appreciated, and are received by the people of the State as well as by men of science everywhere with increasing favor. Requests for copies of the reports are very numerous and indicate a widespread interest. High schools in counties already reported upon have introduced the separate county reports as works to be read by the pupils studying geology, and newspapers publish summaries of reports of local interest.

The object of Prof. L. H. Bailey's Lessons with Plants is well indicated by its secondary title; it is to suggest methods of Nature study; not to teach a science, but only to indicate a way in which plants may be studied and the subject taught. The lessons are an extension of the ideas embodied in the Nature Study Leaflets issued for the use of teachers by the College of Agriculture of Cornell University; while these leaflets are, in turn, the direct growth of "observation lessons" which were a part of the instruction given in itinerant schools of horticulture in the State of New York. When the book is used by the teacher, he is supposed to master an observation, collect specimens proving or illustrating it, and teach his pupils from the specimens. If the pupil consults it, he collects specimens and recites from them, not from the book. Pupils will not do this so well by themselves as when under the inspiration of the teacher; for while it is not true that only those things are useful which one finds out for himself—else we could make little progress—"the pupil should find out something for himself, and, more than all, he should enjoy the finding of it." The lessons teach and picture what are to be found in twigs and buds, leaves and forage, flowers, fruits, the propagation, behavior, and habits, and the kinds of plants; while the appendix contains suggestions on pedagogical methods, books, classification, evolution, the interpretation of Nature, the growing of plants, and a glossary.

Mr. Edward P. Thompson's narrative of the exploration of the Cave of Loltun, near Labná, Yucatan, in 1890-'91, is given as No. 2, Volume I, of the Memoirs of the Peabody Museum of American Archæology and Ethnology of Harvard University. The cave was excavated through all the deposits that had been made in it "down to and into the crystalline surface of the ancient floor itself." Numerous interesting remains of man and human life were found, inscriptions and specimens of art, but nothing indicative of primitive savagery. Typical examples of these relics are represented in figures in the text and in large photographic plates.

D. T. Day's twelfth Report on the Mineral Resources of the United States (1895) appears in a somewhat different form from the previous reports, the pages being enlarged, and is published in two volumes as Part III of the seventeenth annual report of the Geological Survey. In it the scope has been limited more than in previous reports to the statistics of production of the minerals and statements of the conditions of their occurrence, and less space has been devoted to the technical features of their development.

From the United States Geological Survey we have the monographs from the twenty-fifth to the twenty-eighth volume, inclusive. The twenty-fifth volume comprises the survey of the former bed of the very large Lake Agassiz, which occupied the Red River