RECENT TENDENCIES IN BIOLOGY 435 
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 Motu 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 
