vi GENERAL BOTANY 



and to the inanimate forces and materials of their environment ; 

 the cellular structure of plants and its relation to growth, repro- 

 duction, and the anatomy of woody and herbaceous plants ; the 

 phenomena of reproduction, and their relation to crossing, hybridi- 

 zation, and plant breeding. The author has used this portion 

 of the text, with some selections from Part II, as a basis for a 

 semester course in plant biology. 



Parts I and II could, with equal advantage, be combined as 

 the basis for a course on the higher plants during the latter 

 portion of the college year. 



Part II deals with the morphology, life histories, and evolution 

 of the main plant groups. In the chapter devoted to the fungi 

 emphasis is placed upon the nature of enzymes and fermenta- 

 tion and upon the relations of these processes to parasitism, 

 disease, and decay. This chapter also gives an introduction to 

 the important aspects of fungi related to plant diseases and plant 

 pathology. In the treatment of the higher spore-bearing and 

 seed plants the author has given nearly equal attention to the 

 evolution of structure and to reproduction, instead of placing 

 the main stress upon reproductive features, as is often done in 

 elementary textbooks. In the parts relating to structure the 

 teachings of the newer anatomy are followed. This method of 

 treatment has been found to be simpler pedagogically, and more 

 in accord with modern botanical knowledge, than the usual 

 presentation based upon the older anatomy. 



Part III is intended to serve as an introduction, to field work 

 and to the study of the interesting biological and economic 

 aspects of a few important families and species represented in 

 the spring flora. To this end considerable space is allotted to the 

 study of trees and their importance to man. The main problems 

 of forestry are emphasized concretely in connection with the 

 life of a few selected species of forest trees. The herbaceous 

 species of the monocotyledons and the dicotyledons are also 

 treated from their biological and economic aspects, in order to 

 indicate, if possible, the point of view from which additional 

 species may be studied. 



