2 INTRODUCTION TO PART I 



by the use of nucleic acid antimetabolites, and considerations of disturb- 

 ances of function that radiation may cause. Development is not restricted 

 to embryonic life, but continues through the life of the organism, and we 

 will hear not only what radiation may do long before the embryo has a 

 brain, but also what man-made radiation and radiation from outer space 

 may be doing during adult life. 



Samuel P. Hicks 



