34 



range of form, in a materially greater degree of variability 

 within that range, than the 43 species of the other." 



Next I may take the Eoses. Here, again, the specific 

 names are borrowed from Mr. Baker's monograph of the British 

 Roses. But in this case a different rule is followed, and the 

 arrangement is under 13 groups one of them, Eosa canina, 

 being credited with 29 varieties. Bentham only allows five 

 species in all ; whilst Professor Babington, omitting two, since 

 admitted not to be British, gives 17. What Mr. Watson 

 seriously thinks of the value of Mr. Baker's species, we find in 

 his " Compendium." After pointing out the differences between 

 the Bakerian names as given in 1864 and 1869, he says : 



" These uncertainties show that the various forms of our wild 

 roses are so connected by the interchange and crossing of 

 technical characters, only imagined to be diagnostic between 

 them, that the book species really depend on an arbitrary 

 preference given to this or that set of characters, as indicating 

 affinity, and as necessitating union or severance. Contrast tho 

 diagnoses of rubiginosa and micrantha, for instance ; and then 

 compare the description of their varieties with the words of their 

 specific diagnosis. It will be seen that the diagnostic characters 

 of one species appear as the varieties of the other species " 

 (p. 507). 



But if Mr. Watson now accepts Professor Babington and Mr. 

 Baker as infallible authorities in their respective dominions, he 

 begins to apply a method of selection in the matter of the 

 Hieracia, which he tells us are taken "almost exclusively " from 

 Mr. Backhouse's work, " British Hieracia." The London 

 Catalogue gives 35 species, Mr. Bentham only 7. 



If, however, there are materials more or less complete for 

 determining the value of names in the groups already men- 

 tioned, what shall be said of ' ' Eanunculus aquatilis " ? Instead 

 of the single species of Bentham, we have in the London 

 catalogue 8 forms given as species, with 10 varieties. The Com- 

 pendium allows only four, the number which Eay had given in 

 his Botany. " On the whole," says Mr. Watson, " it may be said 



