INTRODUCTION 



I his is your introduction to a book which is written to help you gain an 

 understanding of the science of animal life. Perhaps you are wondering 

 whether you need or want this information and why such subject matter 

 forms a part of a college curriculum. Your course of study will usually 

 include three kinds of material — (1) tool subjects, such as composition and 

 speech training in various languages, which aid you in gathering or imparting 

 ideas, or mathematics and logic, which offer training in reasoning and the use 

 of abstract ideas; (2) technical subjects in which you can acquire the pro- 

 fessional training that will aid you in earning a livelihood when college days 

 are over; and (3) cultural subjects in which you become better acquainted 

 with your social heritage, the rich background of man's artistic contributions 

 in literature, music, and the arts and his intellectual attainments in the fields 

 of religion, philosophy, and science. In this book you will find a general 

 survey of the facts and theories that constitute a particular branch of science. 



So many of our activities are made easier, or are indeed even made possible, 

 by the applications of science that it is sometimes said we live in an age of 

 science. The automobile and airplane, radio and television are accepted parts 

 of our lives, carrying us literally and figuratively over all the world, increasing 

 our information, and adding to the pleasure of our existence. Most of us prob- 

 ably consider inevitable and not particularly surprising the widespread use of 

 atom-powered ships at sea and in the air, and of solar batteries to harness 

 energy from the sun, which we are told to expect in the not too distant future. 

 So accustomed are we to the continued march of marvels in our age that we 

 may forget our indebtedness to the basic knowledge of nature which has been 

 applied in such countless ways for our benefit. 



From agriculture, as from industry, we receive indirectly the fruits of science. 

 Crop rotation as well as erosion control save the soil. Domesticated animals 

 are improved with respect to egg or milk production. Disease-resistant grains 

 are found, and new types of fruits and vegetables are propagated. New chemi- 

 cals are introduced to help in the never-ending war with the enemies of our 

 food supply — insects, fungi, weeds. The experiment station is a recognized 

 part of colleges of agriculture throughout our country. Long-range weather 

 forecasting now benefits both rural and urban dwellers, whether in planting 

 and harvesting crops or in planning recreational activities. But the national 

 problem of water shortage seems far from solution, a challenge to the accumu- 

 lation and application of necessary information. 



The life span of man has been increased by the applications of science which 

 we find in the practice of medicine. Against polluted foods and against the 

 spread of disease we have a measure of protection undreamed of a hundred 

 years ago. No longer do plagues bring terror to a district, although diseases 

 such as the common cold and cancer remain unconquered. Preventive meas- 

 ures against smallpox and typhoid fever are almost universally used, and 

 inoculations to prevent other diseases and to aid in their cure have a wide 

 acceptance. Antibiotics, such as penicillin and aureomycin, are notable con- 

 tributions of science to the control of disease. The study of many problems 



