vi Preface. 



to meet the requirements of elementary students and to 

 interest them in the scientific and aesthetic beauty of plant 

 biology. 



I wish to acknowledge the help I have received from 

 discussions with Prof. F. O. Bower, Sc.D., F.R.S., Prof. 

 J. Joly, Sc.D., F.R.S:, Mr. W, R. G. Atkins, O.B.E., Sc.D., 

 and Mr. N. G. Ball, M.A. I am also greatly indebted to 

 the last three for their kindness in reading the proofs. 



H. H. D. 



SCHOOL OF BOTANY, TRINITY COLLEGE, 

 DUBLIN, April, 1922. 



