85
See also: Classification of living things 82–83 ■ A system for identifying all nature’s organisms 86–87 ■ Microbiology
102–103 ■ Thermoregulation in insects 126–127ORDERING THE NATURAL WORLD
Van Leeuwenhoek examined
samples of rainwater and stagnant
pondwater and marveled at the
multitude of life he saw there. He
identified single-celled protozoa,
naming them “animalcules,” and
went on to discover bacteria. He
also made many observations of
human and animal anatomy,
including blood cells and sperm.
While van Leeuwenhoek
examined water samples, fellow
Dutchman Jan Swammerdam was
placing insects under his own
microscope. He published records
of all manner of insects depicted in
the finest detail and uncovered
much about their anatomy.
Swammerdam’s most influential
work was Life of the Ephemera
(1675), which recorded in great
detail the life cycle of the mayfly.
In England, Nehemiah Grew
used microscopy to examine a
wide range of plants. He was the
first to identify flowers as being
the sexual organs of plants. In The
Anatomy of Plants (1682), Grew
named the stamen as the male
organ and the pistil as the femaleorgan. Grew also spotted pollen
grains and noted that they were
transported by bees.
Since the early days of
microscopy, devices have grown
in sophistication. The electron
microscope, first used in 1931, uses
beams of electrons—rather than
light—to reveal objects, allowing
scientists an even closer look.
Electron microscopes provide views
of up to one million times actual
size—600 times greater than most
modern light microscopes. ■Robert Hooke Born on the Isle of Wight, England,
Hooke showed an early interest
in science. A small inheritance
allowed him to attend the
prestigious Westminster School,
where he excelled, earning a place
at Oxford University. There he
assisted the natural philosophers
John Wilkins and Robert Boyle.
In 1662 Hooke became the first
curator of experiments for the
Royal Society of London. In 1665
he became Professor of Physics at
Gresham College.
Like many scientists of his
day, Hooke had a broad range of
interests. His achievementsinclude some early insights into
the wave theory of light; the
construction of some of the
earliest telescopes; and the
formulation of Hooke’s Law.
Hooke was also a respected
architect, an activity that made
him a wealthy man.Key works1665 Micrographia
1674 An Attempt to Prove
the Motion of the Earth
1676 A Description of
Helioscopes and Some
Other InstrumentsThe compound eye and brain of a
bee, drawn by Jan Swammerdam and
published in A Treatise on the History
of Bees, shows the eye exterior (left)
and the eye dissected (right), with the
brain cross-sectioned below.[Micrographia is] ... the
most ingenious book that I
ever read in my life.
Samuel Pepys
English diaristUS_084-085_The_Microbiological_Environment.indd 85 12/11/18 6:24 PM