CHAPTER VI 



THE BIOLOGICAL SCIENCE OF THE MODERN 

 PERIOD: THE CELL-DOCTRINE 



Having outlined the historical significance of science in 

 general and of biological science in particular, representative 

 features of modern biology may now be considered. In 

 common with all branches of science, modern biological 

 science is more significant in human affairs through its 

 influence upon the point of view than for its material achieve- 

 ments. Biology touches human life at so many angles that 

 it is particularly adapted to illustrate the place now occupied 

 by science in general within the lives of men. The biological 

 sciences occupy a position intermediate between the sciences 

 of inanimate matter and the less exact social sciences that 

 deal with human behavior. An exhaustive survey of the 

 biological field will not be attempted, but rather an outline 

 of its broader features by means of concrete illustrations. 

 The development of biological science * during modern 

 times has been so diversified that we are first impressed 



1 The term biological science may be used broadly to include all fields of 

 knowledge which are mainly concerned with the activities of living bodies 

 whether of unicellular organisms or of men. In the more restricted sense, 

 however, the term includes zoology, botany, the medical, agricultural, and 

 similar sciences which depend most directly upon a knowledge of animals and 

 plants. In the present chapter the term is used in its restricted meaning 

 unless otherwise explained. Classification of science is, of course, arbitrary. 

 There are no sharp distinctions in nature such as have come to exist within 

 our minds. The same physical and chemical changes are found within the 

 living body as in non-living matter. But since the phenomena of life still 

 seem unique in many respects, we may, for convenience, make the broad 

 distinction between the Physical Sciences, such as Chemistry, Physics, Astron- 

 omy, and the like, and the Biological Sciences, such as Botany, Zoology, 

 Medicine, Agriculture, and their subdivisions. The Social Sciences might be 

 placed in a third category, although, biologically speaking, they may be re- 

 garded as a form of Animal Behavior. 



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