TWENTIETH CENTURY ZOOLOGY.

Animal Life.

A First Book of Zociogy. By President DAVID STARR JORDAN and VERNON L. KELLOGG, M. S., Professor of Entomology in Leland Stanford Junior University. 12mo. Cloth, $1.20.

"I believe it is an excellent thing, filling a gap that has long been apparent in our nature work in this country."-Prof. Lawrence Bruner, University of Nebraska.

"Your book is certainly an admirable discussion of biological problems up to date. It is interesting, and stimulative of thought and observation."-Elliott R. Downing, University of Chicago.

"The ecological treatment of zoölogy here finds a truly successful exhibition, and it is certainly very satisfactory and ahead of all previous attempts at a similar exposition for beginners in zoölogy."Prof. Julius Nelson, Rutgers College.

"It is by far the best text-book on zoölogy yet published for the use of high-school students. It breathes the freshness of nature. Fortunate is the school that is permitted to use it.”—Principal W. N. Bush, Polytechnic High School, San Francisco, Cal.

Animal Forms.

By President DAVID STARR JORDAN and HAROLD HEATH, Ph.D., Professor of Zoology in Leland Stanford Junior University. 12mo. Cloth, $1.10.

"Animal Forms" deals similarly with animal morphology, structure and life processes, from the lowest, simplest, one-celled creations to the highest and most complex. The two complete a full year's work in zoology.

The first chapter defines zoölogy, and explains minutely the morphology of a typical animal. The second chapter discusses cells and protoplasm, and prepares the pupil for an intelligent and logical study of the general subject.

In simplicity of style, in correctness of scientific statement, in pro fuseness and perfectness of illustration, these books are without a peer. A Laboratory Manual is in preparation. Teachers' Manuals free.

D. APPLETON AND

COMPANY, NEW YORK.

BOOKS BY PROFESSOR GROOS.

The Play of Man.

By KARL GROOS, Professor of Philosophy in the University of Basel. Translated, with the author's coöperation, by Elizabeth L. Baldwin, and edited, with a Preface and Appendix, by Prof. J. Mark Baldwin, of Princeton University. 12mo. Cloth, $1.50 net; postage, 12 cents additional.

"A book for parents to read and ponder over with care and mental diligence."-Chicago Tribune.

“Not alone does the work make an appeal to the strictly scientific. The general reader will find in it absorbingly interesting facts, presented in a way which may prove of practical use."—Boston Advertiser.

"A very valuable book. The results of Professor Groos's original and acute investigations will be especially appreciated by those who are interested in psychology and sociology, and they are of great importance to educators."—Brooklyn Standard Union.

The Play of Animals.

By KARL GROOS. Translated, with the author's coöperation, by Elizabeth L. Baldwin, and edited, with a Preface and Appendix, by Prof. J Mark Baldwin, of Princeton University. I2mo. Cloth, $1.75.

"A work of exceptional interest to the student."-San Francisco Argonaut.

"His work is intensely interesting. Both nature and books have been ransacked for materials, and the selection shows a trained intelligence of the highest order in observation and acumen."-The Independent.

D. APPLETON AND COMPANY, NEW YORK.

BOOKS FOR NATURE LOVERS.

Insect Life. (New Edition in Colors.)

By JOHN HENRY COMSTOCK, Professor of Entomology in Cornell University. With 12 full-page plates reproducing Butterflies and various Insects in their natural colors, and with many wood-engravings by Anna Botsford Comstock, Member of the Society of American Wood-Engravers. 8vo. Cloth, $1.75 net; postage, 20 cents additional.

"The arrangement of the lessons and experiments and the advice on collection and manipulation are only some of the very admirable features of a work that must take first place in the class to which it belongs."-Philadelphia Press.

'Any one who will go through the work with fidelity will be rewarded by a knowledge of insect life which will be of pleasure and benefit to him at all seasons, and will give an increased charm to the days or weeks spent each summer outside of the great cities. It is the best book of its class which has yet appeared."-New York Mail and Express.

The Art of Taxidermy.

By JOHN ROWLEY, Chief of the Department of Taxidermy in the American Museum of Natural History. Finely illustrated. 12mo. Cloth, $2.00.

CONTENTS.-Collecting. Tools and Materials. Casting. Birds. Mammals. Fish, Reptiles, and Crustaceans. Skeletons. The Reproduction of Foliage for Groups.

“Mr. Rowley will long be gratefully remembered by taxidermists, amateurs, and others, for the care he has used in thus meeting a longfelt want."-Bangor (Me.) Sportsman.

"The book is not an elaborate treatise upon the abstract principles which lie at the foundation of artistic taxidermy, but is rather a compendium full of practical hints and suggestions, recipes, and formulas for the working taxidermist."-The Dial.

D. APPLETON AND COMPANY, NEW YORK.