OT BLACKWELDER, Associate Professor of Geology, University of
Wisconsin, and HARLAN H. BARROWS, Associate Professor of General
Geology and Geography, University of Chicago.

$1.40

An introductory course in geology, complete enough for college
classes, yet simple enough for high school pupils. The text is
explanatory, seldom merely descriptive, and the student gains a
knowledge not only of the salient facts in the history of the earth,
but also of the methods by which those facts have been determined. The
style is simple and direct. Few technical terms are used. The book is
exceedingly teachable.

The volume is divided into two parts, physical geology and historical
geology. It differs more or less from its predecessors in the emphasis
on different topics and in the arrangement of its material. Factors of
minor importance in the development of the earth, such as earthquakes,
volcanoes, and geysers, are treated much more briefly than is
customary. This has given space for the extended discussion of matters
of greater significance. For the first time an adequate discussion of
the leading modern conceptions concerning the origin and early
development of the earth is presented in an elementary textbook.

The illustrations and maps, which are unusually numerous, really
illustrate the text and are referred to definitely in the discussion.
They are admirably adapted to serve as the basis for classroom
discussion and quizzes, and as such constitute one of the most
important features of the book. The questions at the end of the
chapters are distinctive in that the answers are in general not to be
found in the text. They may, however, be reasoned out by the student,
provided he has read the text with understanding.

AMERICAN BOOK COMPANY

ESSENTIALS OF BIOLOGY

By GEORGE WILLIAM HUNTER, A. M., Head of Department of Biology, De
Witt Clinton High School, New York City.

$1.25

This new first-year course treats the subject of biology as a whole,
and meets the requirements of the leading colleges and associations of
science teachers. Instead of discussing plants, animals, and man as
separate forms of living organisms, it treats of fife in a
comprehensive manner, and particularly in its relations to the
progress of humanity. Each main topic is introduced by a problem,
which the pupil is to solve by actual laboratory work. The text that
follows explains and illustrates the meaning of each problem. The work
throug