IV. 



Tt is too much to expect that a work of this kind will be 

 free from mistakes, and I hope that readers will help me by 

 pointing out any corrections that should be made, or by offer- 

 ing suggestions for the improvement of the key. 



Since, in the key to the species, and in the section of 

 ecological notes the genera are arranged alphabetically, and 

 a full table of contents is given for the sections dealing with 

 the plant succession and economic applications, it has not been 

 thought necessary to add an index. 



J. W. BEWS. 

 JSTatal University College, July, 1918. 



