PREFACE Xlll 



demonstrated by twenty years of trial to possess large 

 teaching value. Thus, for example, we have Ascophyllum 

 Sphagnum, Anthoceros, Cycas, and Erythronium in the 

 text, to be supplemented by Fucus, Polytrichum, Marchan- 

 tia, Zamia, and Trillium in the laboratory. By this plan, 

 the laboratory work can never degenerate into merely 

 having the student pretend to " verify" the statements in 

 the text. 



It is anticipated that a laboratory guide, planned to 

 accompany this text and carry out the idea just outlined, 

 may soon become available. 



In the matter of illustrations, the author has been most 

 fortunate in being able to command the services of Miss 

 Maud H. Purdy for the preparation of all original draw- 

 ings, and of Mr. Louis Buhle, photographer at the Brook- 

 lyn Botanic Garden, in making most of the photographic 

 negatives and prints not otherwise acknowledged in the 

 legends. For those so acknowledged the author expresses 

 here his best thanks to authors and publishers who have 

 freely granted permission to reproduce copyrighted as 

 well as uncopyrighted illustrations. The collections of 

 living plants, photographs, and drawings at the Brooklyn 

 Botanic Garden have been freely at the disposal of the 

 author, and grateful recognition is here made to that insti- 

 tution for the exceptional opportunities which it has 

 afforded. 



Special appreciation is here recorded for permission from 

 Prof. David M. Mottier and Prof. Harlan H. York to 

 reproduce, in advance of their own publication, Figs. 8 

 and 263, respectively. 



Specifically, acknowledgment is made to authors and 

 publishers, for permission to reproduce illustrations as 



