EIGHTEENTH CENTURY 
Stephen Hales 
(b. Bekesbourne, Kent, England, September 7, 1677. 
d. Teddington, near London, January 4, 1761). 
Brilliant experimentalist, and one of the founders of plant 
physiology. Vegetable static ks (1727) . First to make experiments 
in transpiration, plant growth and root-pressure; one of the 
first to prove that the solid substance of plants is largely de- 
rived from the air. Fellow of the Royal Society; honored bv an 
inscription in Westminster Abbey. 
Linnaeus (Carl von Linne) 
(£. Rashult, Sweden, May 23, 1707. 
d. Upsala, January 10, 1778). 
Father of modern systematic botany. Professor in Upsala for 
thirty-seven years. Defended the fixity of species, asserting that 
“There are as many species as were created in the beginning’’. 
In his Sy sterna naturae (1735) he adopted a simple artificial sys- 
tem of classification. Philosophia bolanica (1751). His Speciis 
plantarum (1753) is the starting point of binomial nomen- 
clature. 
Johann Hedwig 
(b. Kronstadt, Transylvania, October 8, 1730. 
d. Leipzig, February 18, 1799). 
Physician. Professor of botany in Leipzig (1789-1799). His Fun- 
damentum historiae naturalis mu scorn m fr ondosorum (1782-1783) 
marks the beginning of the systematic study of the mosses. He 
mistakenly considered the antheridia as anthers, the capsule as 
a fruit, the spores as seeds, and the protonema as a cotyledon. 
Michel Adanson 
( b . Aix, Provence, France, April 7, 1727. 
d. Paris, August 3, 1806). 
Historian of botany. Opposed the system of Linnaeus, and 
urged the desirability of classifying plants in natural families. 
Histoire de Botaniqne (1764); Families des plantes ( 1763). First 
described the movement of Oscillator ia (1767). 
Antoine Laurent de Jussieu 
( b . Lyons, France, September 19, 1748. 
d. Paris, September 17, 1836). 
First Director of the Jardin des plantes (1793). Studied with his 
uncle, Bernard de Jussieu. In his Geneva plantar nm secundum 
ordines natur alis disposita (1789) he adopted three main groups— 
Acotyledones, Monocotyledones, Dicotyledones— and under these 
groups, for the first time, described plant families (long called 
orders), one hundred in number; under families he described the 
genera. Linnaeus declared himself unequal to the task. Jussieu 
was called, by Richard, “the first botanist in Europe”. 
Jan Ingen-Housz 
(b. Breda, Holland, December 8, 1730. 
d. Bowood, near London, September, 1799). 
Physician to the Emperor of Austria; later, a resident in England. 
Early plant physiologist. He was the first clearly to demonstrate 
that both sunlight and leaf-green are necessary for the fixation 
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