4 PBEFA CK 



The descriptive text follows in tlie iii:iin tlie sequence of to]iics of 

 Gray's " i^essons in Botany," and ce)'taiii parls of tliatboolc liavr licen 

 retained, as occasional paragraplis will show. In view of the relation 

 of the present book to the '• Lessons " as indicated on the title-page, 

 the writer has felt free to adopt the phraseology of Dr. Gray wherever 

 desired, witliout quotation marks. A consideralde nundier of descrip- 

 tive terms and definitions ap2:)lied to the leaf and tlie flower have 

 been taken from the " Lessons," being now placed apart, for tlie use 

 of the classes making a somewhat detailed stmly of jihanerogams in 

 a systematic way. liut the greati'r jiart of the descriptive text 

 tliroughout is new, the chapters on cryi'togams and on pihysiology 

 being entirely so. 



In an endeavor to combine the best features of new'er methods 

 with the lucidity and definiteness which have given Dr. Gray's text- 

 'nooks their extraordinary merit, the present book departs from its 

 predecessor in paying more attention to the life of plants, as con- 

 trasted with mere form. The wiiter has aimed to give due promi- 

 nence to function which underlies form, that is to physiology and the 

 relations of jilants to their surroundings. Yet while .seeking properly 

 to emphasize the ecological aspects of plant life, he believes that ecol- 

 ogy should not be made the liasis of elementary botany. It seems to 

 him that a course should be built primarily upon a carefid study of 

 form, leading to some power of intelligent discrimination in morplnil- 

 ogy and of accurate description in the technical language of the 

 science. Equally essential are ceitain pierfectly definite princip>les of 

 vegetable physiology. The core of any rational elementary cour.se 

 is thus believed to be concrete, eniliodied in precise and more or less 

 technical language, and measurably endowed with a quality which 

 some would with disfavor characterize as formalism. The writer be- 

 lieves that the body of concrete instruction is not likely soon to be 

 displaced by the less definite and as yet more tentative generalizations 

 of the latest Ecology. 



The Appendix is an essential part of the book, but is prinnirily 

 addressed to the teacher. It contains suggestions in regard to e(piip- 

 ment, books, materials, experiments, and additional exercises, as w ell 

 as pedagogical methods. ■ 



The writer appreciates, and here takes occasion to acknowledge, 

 the care with which Mr. C. E. Faxon and j\Ir. F. Schuyler JLrthews 

 have made many new- drawings for this book. Thanks are due to the 

 staif' of the Gray Herbarium for aid in proof reading, especially to 

 Miss M. A. Day, Librarian. The writer is deeply indebted for advice 

 and criticism to Mr. William Orr, Principal of the High School, 

 Springfield, jNIassachusetts. Above all, tlie writer wo\ild acknowledge 

 his great obligation to Dr. B. L. Rolnn.son, Asa Gray Professor of 

 Systematic Botany in Harvard University. 



E. G. LEAVITT, 



