13 



hardly any genus throughout the whole range of botanical science, 

 does so much uncertainty prevail with regard to the limits of species, 

 as in the genus Rubus : and it really must afford great comfort to bo- 

 tanical tyros, who have been puzzled by these most vexatious plants, 

 to find that the gi'eat masters in Botany, — those who have paid par- 

 ticular attention to this difficult genus, are so completely at fault in 

 their endeavours to determine the species, as the conflicting opinions 

 appended to the descriptions of the fonns an*anged under the fruti- 

 cose or bramble division of the genus, most evidently show them to 

 be. Nor, after the perusal of these opinions, can we feel any surprise 

 at finding the following remarks from the pen of Mr, Leighton himself, 

 who is well known as an ardent botanist. "To the examination of the 

 Shropshire brambles I devoted two successive summers, and collected 

 specimens of every form which came under my notice, in which any 

 conspicuous differences were observable. But, notwithstanding some 

 care and attention, the strange and inconstant manner in which simi- 

 lar forms, and even what were apparently distinct ones, in innumera- 

 ble instances varied or ran into each other, precluded me fi'om arriving 

 at any definite conclusions as to the limits and true characters of the 

 estimated species, and in fact left me in a complete maze of doubt 

 and ignorance whether they should not all be considered as modifica- 

 tions endlessly varied of one and the same species." Mr. Leighton 

 then distributed his specimens to Nees von Esenbeck, Professor Lind- 

 ley and Mr. Bon-er, and solicited their opinions. " In consequence, 

 howevei", of their severally referring the same forms, in many instances, 

 to different and opposite species, I found that no other alternative was 

 left to me than to describe from the specimens submitted to them the 

 various forms of the genus, and append to each description their opin- 

 ions and remarks." 



We are very glad that Mr. Leighton has prefaced these descriptions 

 with the well-known and often-quoted observations on the genus by 

 Mr. Borrer* and Professor Lindley,t because we believe that the fact 

 of the uncertainty respecting species which prevails in many British 

 genera, though perhaps in none to so great a degi-ee as in Rubus, can- 

 not be too frequently or too prominently brought forward. For as in 

 politics " agitation " is the watch-word when a party would attain an 

 object on which they have set their affections, even so must the same 

 means be resorted to whenever the energies of the cultivators of sci- 

 ence are to be awakened, and their exertions directed to any desired 



* Hook. Br. Fl. i. 24.5. f Synopsis, 2nd. ed. 91. 



