PREFACE. 



IN the preparation of the present volume on the Meta- 

 bolic Processes of Plants two alternatives were presented; 

 the one to give as full an account as possible of the 

 literature, the other to give such an account as would 

 form a basis for further study. The latter, and more 

 difficult task, was chosen ; for, valuable though a digest 

 of the relevant literature would be, it would tend to 

 confuse rather than to assist the student. For this 

 reason we do not profess to have mentioned all research 

 on the subject matter ; indeed in some instances, the 

 chapter on Growth for example, some critics will say 

 that too much has been omitted ; we trust, however, that 

 no work of outstanding importance and requisite for our 

 treatment has been omitted. Details regarding methods 

 of experiment have been omitted since this aspect of the 

 subject more properly belongs to a practical treatise. 



P. H. 

 T. G. H. 



July, 1922. 



