2 A TEXTBOOK OF THEORETICAL BOTANY 



of plants is termed Physiology, to which may be added the study of the 

 chemistry of plant Hfe, Biochemistry ; then there is the study of their 

 development, Embryology ; the study of classification, Taxonomy ; and 

 the study of inheritance, Genetics. We may investigate their mode of 

 living, Bionomics, or the relationship between the plant and its habitat, 

 Ecology. Then, again, the investigation of certain groups of plants has 

 become frequently a separate sub-science, and we speak of the study of sea- 

 weeds as Algology ; of fungi as Mycology ; of plant diseases as Plant 

 Pathology ; of bacteria as Bacteriology. There are also certain economic 

 branches of the subject which are more familiar to the man-in-the-street : 

 Horticulture, the study of garden plants ; Forestry, the study of trees ; 

 Agricultural Botany, the study of crop-plants ; and Pharmacognosy, the 

 study of drug-plants ; all of which form part of Economic Botany. 



This, then, may be said to be an outline of the general scope of the science 

 of Botany, which is certainly very different from the popular conception. 

 Moreover, it is important to realize that each of these sub-sciences is dependent 

 upon the others, and that a clear understanding of any one field is impossible 

 without a fundamental knowledge of the essential features of the whole 

 subject. In fact, it is equally true to say that a proper knowledge of Botany 

 cannot be obtained without at the same time gaining an elementary knowledge 

 of the essential features of the whole of Natural Science, that is of the allied 

 sciences of Chemistry, Zoology, Geology and Physics. So dependent are 

 the sciences upon one another, and at the same time so extremely complex 

 has each of them become, that one of the greatest problems which besets a 

 scientist at the present day is how he can become familiar with the details 

 of his own particular section, while, at the same time, remaining acquainted 

 with the current position of the allied branches of science. One of the 

 greatest dangers which we are facing at the present time is the tendency to 

 over-specialization, that is to say, the cultivation of an intensive but exclusive 

 knowledge of a very small part of science with the inevitable result of losing 

 touch with the whole. Such an outlook may advance our knowledge in 

 some particular field of research, but what science needs more than anything 

 else is to be able to take stock of herself, to see whither all modern research 

 is leading, and what advantage, if any, the human race has received in return 

 for all the energy which has been expended. Only by being capable of under- 

 standing the fundamental facts in dift'erent branches of a science and of 

 various sciences, can such an estimate be made, and it is very important 

 that at the outset of his career a student should attempt to provide himself 

 with the necessary knowledge, for very soon he may be swept up in the 

 train of specialization and fall into danger of losing his sense of proportion. 



The Characteristics of Living Organisms 



Before commencing our study of Botany it is necessary for us to inquire 

 how w^e may distinguish living organisms from dead matter ; in other words, 

 how we may limit the territory designated as Biology. 



