496 SCIENCE PROGRESS 



organic chemistry. If a student of the problem is ever to pass 

 from the contemplation of the work of his colleagues to experi- 

 ment, then he must resolutely close his eyes to many of these 

 alluring possibilities and, concentrating his attention upon one 

 feature of the problem, learn by experience what facilities 

 physical and chemical methods provide him for its experimental 

 solution. 



In these pages an attempt has been made to consider the 

 enzyme as a possible agent of synthesis with a view to sub- 

 mitting the problem to subsequent investigation in the 

 laboratory. No one is more conscious than the writer of his 

 inability to treat this side of a general problem with adequate 

 freedom and confidence, and he would greatly appreciate the 

 criticisms and suggestions of others who are more conversant 

 with the questions discussed or who are approaching them from 

 different points of view. 



