An Introduction to Zoology 



By ROBERT W. HEGNER, Ph.D. 



Instructor in Zoology in the University of Michigan 



Only a few animals belonging to the more important phyla, as 

 viewed from an evolutionary standpoint, are considered. They are, 

 however, intensively studied in an endeavor to teach the funda- 

 mental principles of Zoology in a way that is not possible when a 

 superficial examination of types from all the phyla is made. 

 Furthermore, morphology is not specially emphasized, but is 

 coordinated with physiology, ecology, and behavior, and serves to 

 illustrate by a comparative study the probable course of evolution. 

 The animals are not treated as inert objects for dissection, but as 

 living organisms whose activities are of fundamental importance. 

 No arguments are necessary to justify the " type course," de- 

 veloped with the problems of organic evolution in mind, and 

 dealing with dynamic as well as static phenomena. 



" I have read your chapter (The Crayfish and Arthropods in 

 General) and can express my satisfaction with reference to the 

 general arrangement of the matter, as well as with reference to 

 the detail. The whole treatment is up to date, taking account of 

 the modern advancement in our knowledge of the crayfishes, and, 

 chief of all, the more important features in the natural history 

 of these animals are very properly separated from the unimportant 

 ones. I think this chapter gives the essence of what we know 

 about crayfishes, and any student might use the book advan- 

 tageously. In fact, I know no other text-book which gives such a 

 wealth of information upon so few pages." PROFESSOR A. E. 

 ORTHMANN, Carnegie Museum. 



"The plan is very satisfactory, and the book will be very in- 

 structive for class use. I am very glad that you have chosen the 

 bee as your insect type." (Chapter XII.) DR. E. E. PHILLIPS, 

 Department of Agriculture, Washington, D.C. 



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