RECENT TENDENCIES IN BIOLOGY 443 



to establish the same basis for thinking about the organization 

 of the human body as about the rest of the animal series.__ 

 The first triumph of the scientific method was the over- 

 throw of authority as a means of ascertaining truth and sub- 

 stituting therefor the method of observation and experiment. 

 This carries us back to the days of Vesalius and Harvey, 

 before the framework of biology was reared. But the scien- 

 tific method, once established, led on gradually to a belief in 

 the constancy of nature and in the prevalence of universal 

 laws in the production of all phenomena. In its progress 

 biology has exhibited three phases which more or less 

 overlap: The first was the descriptive phase, in which 

 the obvious features of animals and plants were merely 

 described; the descriptive was supplemented by the com- 

 parative method; this in due course by the experimental 

 method, or the study of the processes that take place in 

 organisms. Thus, description, comparison, and experiment 

 represent the great phases of biological development. 



The Notable Books of Biology and their Authors. — The 

 progress of biology has been owing to the efforts of men of 

 very human qualities, yet each with some special distinguish- 

 ing feature of eminence. Certain of their publications are 

 the mile-stones of the way. It may be worth while, therefore, 

 in a brief recapitulation to name the books of widest general 

 influence in the progress of biology. Only those publica- 

 tions will be mentioned that have formed the starting-point 

 of some new movement, or have laid the foundation of some 

 new theory. 



Beginning with the revival of learning, the books of 

 Vesalius, De Corporis Humani Fabrica (1543), and Harvey, 

 De Motti Cordis et Sanguinis (1628), laid the foundations of 

 scientific method in biology. 



The pioneer researches of Malpighi on the minute anat- 

 omy of plants and animals, and on the development of the 



