VI PREFA CE. 



standjioint of the different members of Itie plant, their special 

 function and their special relations to environment. The stem, 

 root, leaf, flower, etc., are carefully examined and their ecological 

 relations pointed out. This together with the study of physiology 

 and representatives in the groups of plants forms a thorough 

 basis for pure plant ecology, or the special study of vegetation 

 in its relation to environment. 



There is a study of the factors of environment or ecological 

 factors, v\'hich in general are grouped under tlie physical, climatic, 

 and biotic factors. This is followed b)- an analysis of vegeta- 

 tion forms and structures, plant formations and societies. Then 

 in order are treated fjrielly forest societies, prairie societies, 

 desert societies, arctic and alpine societies, aquatic societies, and 

 the special societies of sandv, rockv, and marshy places. 



Acknowledgments. The author wishes to express his grate- 

 fulness to all those who have given aid in the preparation of this 

 work, or of the earlier editions of P^lementary Botany; to his 

 associates. Dr. \i. J. iJurand, I^r. K. M. Wiegand, and Professor 

 W. W. Rowlee, of the botanical de])artment, and to Professor 

 B. M. Duggar of the Universitv of Missouri, Professor J- C. 

 Arthur of Purdue Universitv, and Professor W. F. Ganong of 

 Smith College, for reading one or more ])Ortions of the text; 

 as well as to all those who have contriljuted illustrations. 



lUustration-;. The large majoritv of the illustrations are new 

 (or are the same as those used in earlier editions of the author's 

 Elementary Botany) and were made with sj.)ecial reference to 

 the method of treatment followed in the text. Many of the 

 photogra]_)hs were made by the author. Others were contributed 

 by Professor Rowlee of Cornell University; Mr. John CiilTord 

 of New Jersey; Professor B. M. Duggar, Universit'\' of ^Missouri; 

 Professor C. E. Bessey, Uni\ersit\- of Neliraska; Dr. !M. 15. Howe, 

 New York Botanical Garden; Mr. Clifford Pinchot, Chief of 

 the Bureau of iMireslry; INfr. 15. 'P. C.allo\va\', Chief of the 

 Bureau of IMant fnilustr\'; Professor Tuome\' of Yale University; 

 and Mr. I'l. If. Ilarriiiinii, who lln-ough Dr. C. H. Merriara 

 of the National IMuseuni allowed the use of several of his copy- 



