II. INEQUALITY OF SPECIES. 49 



unequal and inexact as'that of order. The term is ap- 

 plied alike to the clearest species and to the merest 

 variety, provided any technical botanist may think fit to 

 describe that variety as a species. It is applied aUke to 

 tlie largest aggregate and to the smallest segregate 

 therefrom [Rubus fruticosus and Rubus argenteus) to 

 which any botanical pretender may give a specific name. 



The inequality or non - equivalence of book -species 

 most seriously impedes the Phyto - geographer in his 

 investigations. He cannot institute any just compari- 

 sons between the botany or vegetation of different coun- 

 tries, unless he can bring their respective species to the 

 same standard of value. A thousand species of India, as 

 fixed and described by Dr. J. D. Hooker, would be far 

 more than equal to a thousand species of Europe, as de- 

 fined by M. Jordan. Suppose that it is wished to insti- 

 tute statistical comparisons between the botany of the 

 British Islands and that of New Zealand or any other 

 country. Are the native species of Thalictrum to be 

 counted three or five ? Are those of the Batrachnim 

 section of Ranunculus to be reckoned two or twelve ? 

 Are we to set down the species of Rubiis at five or 

 at fifty ? Wild as such queries might appear to some 

 readers, they do not exaggerate the actual differences 

 about species, as evinced in the opinions of living bo- 

 tanists. 



The impediments to phyto-geographical investigations, 

 which arise from these uncertainties about species, are 

 by no means limited to questions of number. The iden- 

 tity or otherwise of species in different countries cannot 

 be satisfactorily traced, while the limits of those species 

 are unfixed. Where one botanist sees sameness, another 

 sees only similitude ; where this botanist finds identity, 

 that botanist finds only substitution. The areas and 



VOL. IV. H 



