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The pedagogical importance of laboratory and field study has led to the introduction of a series of exercises upon the structure, physiology, and habits of representative animals. These exercises suggest the more important topics for study rather than give an inflexible outline to be followed in detail. The teacher is thus left free to adapt and modify the laboratory course to suit the peculiar needs of his classes and his equipment. The exercises lead to the study of Systematic Zoology, to which they serve as the natural introduction, the classification of animals being based upon their structural relationships. With the anatomy of the typical forms examined in the practical exercises in mind, the student ought to have no trouble in understanding the structural modifications mentioned in the descriptions of the principal classes and orders. Having thus enlarged his view of the animal kingdom, he is in position to appreciate the elementary facts of Comparative Zoology and to understand the main features of the current zoological theories. Believing this to be a logical sequence of study, the book has been arranged in accordance therewith. With the exception of slight changes, the laboratory exercises are the same as those recommended by the New York State Science Teachers' Association. The system of classification adopted is that given by Parker and Haswell in their "Text-book of Zoology," a work which will long be a standard of reference for teachers in secondary schools. Part I and Part II of Professor Orton's book have been transposed so as to place classification before the dis

cussion of Comparative Zoology. The addition of a chapter on "The Origin of Animal Species" will, it is hoped, enable the student to understand the most important, at least, of zoological theories. A number of new figures have been incorporated. An asterisk at the head of a chapter indicates that the subject-matter of the chapter may be illustrated by practical work, for which directions will be found in the Appendix.

Acknowledgments are due to Messrs. D. Appleton and Company for permission to reproduce Figures 39(11) and 367 from Thomson's "Outlines of Zoölogy"; to the J. B. Lippincott Company for permission to reproduce Figures 207, 208, 212, and 256 from Piersol's "Normal Histology," and Figure 368 from Smith's "Economic Entomology"; to Messrs. W. B. Saunders and Company for permission to reproduce Figure 203 from G. C. Huber's edition of Böhm and Davidoff's "Text-book of Histology," and to Professor Alfred Schaper of the University of Breslau, for permission to reproduce Figure 211 from his edition of Stöhr's "Textbook of Histology."



The first thing to be determined about a new specimen is not its name but its most prominent character. Until you know an animal, care not for its name. AGASSIZ.

The great benefit which a scientific education bestows, whether as training or as knowledge, is dependent upon the extent to which the mind of the student is brought into immediate contact with facts — upon the degree to which he learns the habit of appealing directly to Nature.— HUXLEY.

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