MODERN BIOLOGY 437 



and Saussure — stood in high favour in his native town. After preliminary- 

 studies there, he betook himself to Paris in order to continue his education 

 as a botanist. In the company of Lamarck, Cuvier, and Geoffroy he spent ten 

 years there, during which his reputation increased year by year and public 

 commissions were entrusted to him; amongst other things he was sent, with 

 the financial assistance of the State, on scientific expeditions in different parts 

 of France; Lamarck handed over to him the editing of his French flora and 

 he was finally elected professor at Montpellier. In 1816, however, he returned 

 to Geneva, which during the Revolution had become incorporated with 

 France, but after the fall of Napoleon was again united to Switzerland. He 

 then lived in his native town as professor of botany and member of the high 

 council, honoured and respected until his death, in 1841. 



De Candolle on -plant morphology and physiology 

 De Candolle mastered the whole field of botany better than anyone else in 

 his time; he was at once systematist, morphologist, and physiologist. He 

 started a gigantic work, Prodromus systematis naturalis regni vegetabilis, which 

 was to describe all known plants, but which for obvious reasons was never 

 completed in his lifetime; his son and many others worked at it after his death. 

 The principles on which he classified the vegetable kingdom he laid down 

 in a work published in 18 13 entitled Theorie elementaire de la botanique, which 

 he revised several times and which is without doubt his finest work, worthy 

 'to be associated with, and at the same time representing a great advance on 

 Linnasus's Philosophica hotanica, which doubtless gave him the idea. It starts 

 with a general scientific theory, according to which nature is controlled by 

 four great forces : attraction, and affinity, which are the basis of physical and 

 chemical phenomena, the life-force, which is common to ail living creatures, 

 and sensibility, which is the characteristic of animal life as opposed to vege- 

 table life. Each of these four forces has its own science: physics, chemistry, 

 physiology, and psychology. It is thus a markedly vitalistic conception, 

 which is still more emphasized in such an assertion as that "the life-force 

 annuls or modifies, as necessity dictates, the ordinary laws of matter." De 

 Candolle is by no means a fantastic natural philosopher, however; on the 

 contrary, he has the same sober and critical conception of natural phenomena 

 as Cuvier, whose correlation theory he applies to the vegetable kingdom. 

 He maintains that the two most vital organic systems in the plants, the vege- 

 tative and the sexual, are dependent upon one another; a plant with highly 

 developed fertilizing organs cannot possess primitive vegetative organs, and 

 vice versa; therefore a natural system, set up with comprehensive regard to 

 the entire reproductive organization, should at once conform to such a 

 system set up with a view to the vegetative organs, and this, indeed, he 

 proves by means of examples. In connexion herewith he maintains, under ac- 

 knowledgment to Linnasus, that there is throughout the vegetable kingdom 



