Chap, iii.] the Dogma of Constancy of Species. 143 



The peculiar character of the natural system as compared 

 with every artificial arrangement is brought out into higher 

 relief by Robert Brown than by Jussieu and De Candolle, and 

 he succeeded better than any of his predecessors in separating 

 purely morphological and systematically valuable relations of 

 organisation from the physiological adaptations of organs. 

 While the majority of systematists surrendered themselves to 

 the guidance of a blind feeling in the discovery of affinities, 

 their correct determinations being the accidental result of 

 instinct and unconscious operations of the understanding, 

 Brown endeavoured to give an account to himself in every case 

 of the reasons why he took this or that view of the relationships 

 which he determined ; from what was already established and 

 indubitable he gathered the value of certain marks, in order to 

 obtain rules for the determination of unknown relationships. 

 In this way he discovered also, that marks, which are of great 

 value for classification within the limits of certain groups of 

 affinity, may possibly prove to be valueless in other divisions. 

 Thus Robert Brown in his numerous monographs supplied the 

 model, by which others might be guided in further applying 

 and completing the method of the natural system ; and in this 

 respect he was met by the botanists of Germany in the spirit 

 of the best good-will and most profound appreciation, as is 

 shown by the fact that a collection of his botanical works, 

 translated by different German botanists, was edited, in five 

 volumes by Nees von Esenbeck as early as the period between 

 1825 and 1834. The natural system established itself in 

 Germany through the labours of Brown and De Candolle ; and 

 the more correct appreciation of it as compared with the 

 sexual system of Linnaeus was promoted by a work of Carl 

 Fuhlrott which appeared in 1829, in which the systems of 

 Jussieu and De Candolle are compared with those of Agardh, 

 Bartsch, and Linnaeus, and the superiority of the natural system 

 is clearly set forth. A still greater effect in this direction was 

 produced by the appearance in 1830 of the 'Ordines naturales 



