CHAP, iv Taxonomy 1860-1^00 129 



The other points on which Van Tieghem laid stress seem 

 to be artificial when an examination is made of the whole 

 flora. They link together families which have never 

 hitherto been held to be allied, and they separate others 

 whose affinities have been generally recognized. We can 

 hardly imagine either that such a feature as the mode of 

 differentiation of the root-apex is likely to be a character 

 of diagnostic value on so large a scale as Van Tieghem 

 claimed. 



One very important duty which was discharged in large 

 measure in these years by systematic botanists was the 

 promulgation of the importance of the study of the geo- 

 graphical distribution of plants. It was especially recog- 

 nized and taught by the Kew authorities, who embodied 

 what was known in their treatises on Taxonomy. Bentham, 

 in particular, was very much in earnest on this point, 

 calling attention to it in several of his addresses given as 

 President of the Linnean Society of London, as well as 

 in articles in the contemporary reviews. The result was 

 a great extension of activity in the compilation of Floras, 

 many of them giving the records of large tracts of 

 country, while others dealt with smaller subdivisions. 

 During the later years of the century botanical explora- 

 tion was being pursued with great zest all over the 

 world, the results appearing sometimes in the form of 

 Floras of particular districts, sometimes in that of chapters 

 in the record of travels whose scientific objects were on 

 a wider scale. 



The most important work of this kind in Europe was 

 de Candolle's Prodromus. Originally projected in 1824 it 

 continued to appear till 1873, when the seventeenth and 

 last volume was published. Of it Bentham said ' the 

 Prodromus has been gradually extended into a series of 

 concise monographs by different authors, differing much 

 in merit, but drawn up as nearly as could be according to 



GREEN I 



