rKK,rA\ i'-. Yii 



that it seems important to find a place for them even in an 

 elementary work. The reason for Chapters XVI and XVII 

 has been stated already, and even if Plant Relations is stud- 

 ied, Chapter XVII will be useful either as a review or as an 

 introduction. In the chapter on Plant Physiology the 

 author has been guided by Xoll's excellent resume in the 

 "Strasburger " Botany. 



The illustrations have been entirely in the charge of 

 Dr. Otis W. Caldwell, who for several years has conducted 

 in the University, and in a most efficient way, such labo- 

 ratory work as this volume implies. Many original illus- 

 trations have been prepared by Dr. Caldwell and his assist- 

 ants, and some are credited to Dr. Chamberlain and Dr. 

 Cowles, of the University, but it is a matter of regret that 

 pressure of work and time limitation have forbidden a still 

 greater number. The authors of the original illustrations 

 are cited, and where illustrations have been obtained else- 

 where the sources are indicated. The descriptions given 

 in connection with each illustration are unusually full, 

 and should be studied carefully, as frequently they contain 

 important material not included in the text. 



The author would again call attention to the fact that 

 this book is merely intended to serve as a compact supple- 

 ment to three far more important factors : the teacher, the 

 laboratory, and field work. Without these it can not serve 

 its purpose. 



JOHX M. COULTER. 



THE UXIVKKSITY OF CHICAGO. ^Yocember, 1899. 



