of carbon in plants from the carbon dioxide of the air (photosyn- 
thesis). First to distinguish between photosynthesis and 
respiration (1779). His Experiments on Vegetables (1779) was 
translated into three languages. 
Joseph Gottlieb Kolreuter 
( b . Wi'irtemberg, Germany, April 17, 1733. 
d. Karlsruhe, Baden, November 12, 1806). 
Professor (1762), and director of the Botanic Garden, Karlsruhe 
(1763 1786). First to investigate the sexuality of plants scientific- 
all}'. He was one of the first to explain the purpose of nectar 
and the function of insects in pollination. He produced the first 
plant hybrids. His important work Preliminary account of a few 
experiments and observations concerning the sex of p/ants, was 
published between 1761 and 1766. 
EARLY NINETEENTH CENTURY 
Augustin Pyrame de Candolle 
(b. Geneva, February 4, 1778. d. Geneva, September 9, 1841). 
Famous systematise Professor in Geneva. Theorie elementaire 
de la botanique (1813, 1819). His Prodromus system atis naturalis 
regni vegetabilis, begun in 1824, and continued for fifty years, was 
called by Sachs “the grandest work of descriptive botany yet in 
existence”. First to classify plants into vascular and non- 
vascular (cellular). The amount and compass of his labors are 
said to exceed those of any botanist before or after him. 
Robert Brown 
(b. Montrose, Scotland, December 21, 1773. 
d. London, June 10, 1858). 
Librarian to Linnaean Society (London). Custodian of the 
British Museum (1823-1858). Discovered and made the first 
detailed study of the nucleus. Called by Humboldt “ Botanicorvm 
facile princeps" . Discovered the gymnospermy of cycads and 
conifers (1827). Collected nearly 4000 new species of plants in 
Australia (1801-1805) . First to distinguish clearly the embryo-sac, 
the integments and nucellus of the ovule, and to interpret cor- 
rectly the hilum, the micropyle, and the endosperm. 
Thomas Andrew Knight 
( b . Wormsesly Grange, Ludlow, Herefordshire, England, 
August 12, 1759. d. London, May 11, 1838). 
Horticulturist, physiologist, and first English plant-breeder. 
Fellow of the Royal Society (1805), Copley medalist (1806). One 
of the founders and president of the Horticultural Society (1811- 
1838). Did important work in the improvement of cultivated 
plants. First to demonstrate experimentally that the direction 
of growth of roots and stems is due to the influence of gravity. 
Johann Heinrich Friederich Link 
(b. Hildersheim, Germany, February 2, 1767. 
d. Berlin, January 1, 1851). 
Professor of Botany and director of the Botanic Garden in Berlin 
(1815-1851). Author of the Gottingen prize essay (1804), Grund- 
lehren der Anatomie und Physio Logie der Pflavzen, in which he 
demonstrated that all algae, fungi and lichens are plants, and 
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