2 THE NATURE OF BOTANY 



MORPHOLOGY considers the form and structure of plants. It 

 considers the forms of plant bodies and the organs and tissues 

 which compose them. Morphology studies the structure of 

 roots, stem, leaves, buds, and flowers, and establishes the rela- 

 tionships of organs. Morphology not only considers the more 

 complex plants but also the simpler ones, and traces the develop- 

 ment of plant structures through the different plant groups. The 

 phase of Morphology in which the development of the more 

 complex plants from the simpler ones is studied, is called Plant 

 Evolution. When Morphology is concerned with the micro- 

 scopical study of the finer structures of plants, then it is called 

 Anatomy, and if the study is mainly concerned with the structure 

 of the cell, then it is called Cytology. Anatomy and Cytology are 

 often spoken of as Histology. Another phase of Morphology is 

 Embryology which, as the term suggests, is the study of the 

 embryo, or the study of the plant during its formation in the seed. 



PLANT PHYSIOLOGY studies the functions of plant structures and 

 the relation of these functions to light, temperature, air, soil, etc. 

 It treats of how the plant lives, respires, feeds, grows, and re- 

 produces. In the study of Plant Physiology we learn how plant 

 food is made and transported, and how plants grow. As a basis 

 for the study of Plant Physiology, one must have a knowledge 

 of the Morphology of plants and also a knowledge of Chemistry 

 and Physics. 



PLANT PATHOLOGY treats of plant diseases. In this subject one 

 learns the disease producing plants and how they affect the plant 

 diseased. In the study of Plant Pathology, in order to know how 

 the diseased plant is injured, one must know the nature and 

 function of the tissues attacked. This means that one should 

 know Morphology and Plant Physiology. Furthermore, in order 

 to know how the disease producing form attacks other plants and 

 propagates itself, one needs to know its Morphology and Physi- 

 ology. 



PLANT ECOLOGY considers plants in relation to the conditions 

 under which they live. Some plants can live on a dry hill top, 

 while others can live only in moist, shady places. Some can live 

 in colder regions than others. Some plants, like many of the 

 weeds, can thrive when crowded among other plants, while some 

 like the Corn plant can not. Marshes, bogs, forests, sandbars, 

 etc., all have their characteristic plants. One set of plants often 



