INTRODUCTION 



Before we go farther, you should perhaps be told that you will find many 

 words that will be new to you. Each branch of science has its special vocab- 

 ulary, just as every type of industry or sport has its own list of technical 

 terms. These words will be defined the first time they are used, and many of 

 them will be found in the glossary at the end of this book. Learn to spell 

 these words, to understand their meanings, and to use them correctly. You 

 will enrich your vocabulary as a cultured individual, and you will help your- 

 self in learning the material that is presented in this book. You learn a new 

 vocabulary every time you learn a new game or become a "fan" of some 

 different sport. Be cooperative; help yourself and your teacher by learning 

 the vocabulary of biological science. 



If vour parents used a forerunner of this textbook when they studied zoology 

 in college, they will probably be quite astonished by the many new words 

 they see in scanning this edition. The growth of science in recent decades has 

 been phenomenal, and zoology has shared in this growth. In zoology, as in 

 other areas of science, new techniques and instrumentation have come into 

 use, new discoveries have been made, new insights have revealed new con- 

 cepts. Gradually, whole new fields of knowledge have developed; many of 

 these have become, in the course of time, recognized subdivisions of the 

 general subject. It should be emphasized, however, that such subdivisions, 

 or fields of specialization, have come into being not because of any funda- 

 mental discontinuities in the subject itself; there is, as we have said, a 

 fundamental unity in all human knowledge. In fact, a conspicuous feature 

 of the growth of many special fields in zoology, for example, has been the 

 realization that the solution of zoological problems requires the use of tech- 

 niques and concepts of physics and chemistry. The compartmentalization 

 of knowledge into subject fields has come about largely because, in the 

 sciences particularly, information has increased so rapidly that it has become 

 impossible for any individual to keep abreast of developments in more than 

 a relatively limited area of knowledge. Thus, he becomes a specialist in 

 one or a few related fields; and, in the words of a current quip, he spends 

 his life learning more and more about less and less. No specialist, however, 

 pursues this course to the obvious end of knowing everything about nothing. 



In beginning to tell you what this book is about, we must set forth the 

 names and provinces of a number of scientific fields; but you must remember 

 that these divisions are recognized only for convenience. Science is knowl- 

 edge gained by observing and reasoning, and it is divided on the basis of 

 the source of the observations. Thus, the social sciences deal with knowledge 

 gained by the study of man in his social relations. In the natural sciences, 

 on the other hand, we find two different types of information. First, in the 

 physical sciences, such as astronomy, physics, chemistry, and geology, 

 knowledge of man's non-living surroundings is accumulated. Second, in the 

 biological sciences, botany, zoology, and psychology, knowledge of living things 

 is sought. 



Biology, then, is the science of living things, both plants and animals. 



