6 
HISTORY OF CLASSIFICATION 
the Genera Plantarnm of Antoine Laurent de Jussieu, who is justly con¬ 
sidered the founder of the natural system. He gathered up the best re¬ 
sults of his predecessors, especially those of Ray, Linnaeus, and his uncle, 
Bernard de Jussieu, and conceived a system which truly displayed natural 
affinities. He made it clear that previous systems had broken down be¬ 
cause of relying exclusively on a single character. He chose the Ranun- 
culaceae, the Buttercup Family, to illustrate his principles. By no single 
mark can it be distinguished from all other families, but he showed that 
the combination of all its characters was sufficient to set it off as a natural 
family and that the test for inclusion of a doubtful genus within the family 
was consideration of the aggregate characters of that genus. He made a 
farther highly important deduction that the characters of a family must 
not always be drawn from the same organ. He fell, however, into the 
age-old error that the essential characters for primary groups can be 
determined in advance. 
The wearisome exponents of the higher criticism have objected to the 
honor accorded Laurent de Jussieu, saying that he had the system from 
his uncle, Bernard de Jussieu. This is of no especial importance. The 
work of no great man would be possible save for the arduous labors of 
those who precede him; one element of greatness lies in being able to 
gather up and organize scattered or unrelated results into living and 
forceful propositions of wide application. 
The stimulus given to the study of botanical classifications by the 
work of Jussieu produced wonderful activity in the century immediately 
following. The Nineteenth Century was a century of vast and un¬ 
paralleled labors in botany. Of all the great names in this century one 
of the most remarkable is that magnificent botanical genius, Augustin 
Pyramus de Candolle. He developed with clearness a comparative mor¬ 
phology which was of great value. It rested on his doctrine of the 
symmetry of plants, that is all organisms in their inner nature are reg¬ 
ular, and departures from the original symmetry of a class are due to 
abortion or disappearance of parts, degeneration or reduction of parts, 
and adherence. The morphological basis, therefore, lies in the relative 
position and number of the organs, not in their physiological properties. 
Guided by such a morphology he traced a long series of related forms 
and yet he did not seize upon the idea of affinity through descent. He 
discovered important rules but did not apprehend their real significance. 
DeCandolle projected a great work to include descriptions of all known 
species of flowering plants. The work is entitled Prodromus Systematis 
Regni Vegetabilis, a Forerunner to the System of the Vegetable King¬ 
dom. Prodromus literally means the northeast wind which blows for 
eight days before the rising of the dogstar. The work was intended as 
a forerunner of that natural system which would sometime appear in 
effulgent glory. He had the cooperation of the principal botanists of his 
day and the work was continued after his death by his very great son, 
Alphonse de Candolle. The first volume was published in 1824, the last 
in 1873. The Prodromus blew for fifty years but the dogstar has not 
yet risen. 
The DeCandollean system reached its fullest development in the Genera 
