20 BIOLOGY AND ITS MAKERS 
neers had to be men of determined independence; they labored 
against self-interest as well as opposition from the church 
and the priesthood, and they withstood the terrors of the 
Inquisition and the loss of recognition and support. 
In this uncongenial atmosphere men like Galileo, Des- 
cartes, and Vesalius established the new movement and over- 
threw the reign of authority. With the coming of Vesalius 
the new era of biological progress was opened, but its growth 
was a slow one; a growth of which we are now to be con- 
cerned in tracing the main features. 
Tue Epocus 1n BroLrocicaL HIsToRY 
Tt will be helpful to outline the great epochs of biological 
progress before taking them up for fuller consideration. 
The foundation of progress was the renewal of observation 
in which, as already stated, all modern science was locked up. 
It was an epoch in biological history when Vesalius over- 
threw the authority of Galen, and studied at first hand the 
organization of the human body. 
It was an epoch when William Harvey, by adding experi- 
ment to observation, demonstrated the circulation of the 
blood and created a new physiology. The two codrdinate 
branches of biology were thus early outlined. 
The introduction of the microscope, mainly through the 
labors of Grew, Hooke, Malpighi, and Leeuwenhoek, opened 
a new world to the investigator, and the work of these men 
marks an epoch in the progress of independent inquiry. 
Linneus, by introducing short descriptions and uniform 
names for animals and plants, greatly advanced the subject 
of natural history. 
Cuvier, by founding the school of comparative anatomy, 
so furthered the knowledge of the organization of animals 
that he created an epoch. 
