I he science of biology today is not the same science 

 of fifty, twenty-five, or even ten years ago. 

 Today's accelerated pace of research, aided 

 by new instruments, techniques, and points 

 of view, imparts to biology a rapidly chang- 

 ing character as discoveries pile one on top 

 of the other. All of us are aware, however, 

 that each new and important discovery is 

 not just a mere addition to our knowledge; 

 it also throws our established beliefs into 

 question, and forces us constantly to reap- 

 praise and often to reshape the foundations 

 upon which biology rests. An adequate pres- 

 entation of the dynamic state of modem 

 biology is, therefore, a formidable task and 

 a challenge worthy of our best teachers. 



The authors of this series believe that 

 a new approach to the organization of the 

 subject matter of biology is urgently needed 

 to meet this challenge, an approach that in- 

 FoundationS troduces the student to biology as a grow- 



ing, active science, and that also permits 

 of Modern each teacher of biology to determine the 



level and the structure of his own course. A 

 single textbook cannot provide such flexibil- 

 Series ^^y^ ^"^ ^^ ^^ ^^^ authors' strong conviction 



that these student needs and teacher pre- 

 rogatives can best be met by a series of 

 short, inexpensive, well-written, and well- 

 illustrated books so planned as to encompass 

 those areas of study central to an under- 

 standing of the content, state, and direction 

 of modern biology. The FOUNDATIONS 

 OF MODERN BIOLOGY SERIES repre- 

 sents the translation of these ideas into 

 print, with each volume being complete in 

 itself yet at the same time serving as an 

 integral part of the series as a whole. 



Biology 



