PRESIDENTIAL ADDRESS TO THE BOTANICAL 



SECTION OF THE BRITISH ASSOCIATION. 



By W. T. Thiselton-Dxek, M. A., F. E. S. 

 Director of the Koyal Gardens, Kew. 



(Concluded from Vol. Ill, p. 177). 



Nomenclature. 



There is one subject upon which, from ray official position 

 elsewhere, I desire to take the opportunity of saying a few 

 words. It is that of Nomenclature. It is not on its technical 

 side, I am afraid, of sufficient general interest to justify my 

 devoting to it the space which its importance would otherwise 

 deserve. But I hope to be able to enlist your support for the 

 broad common-sense principles on which our practice should 

 rest. 



As I suppose everyone knows, we owe our present method 

 of nomenclature in natural history to Linnaeus. He devised 

 the binominal, or, as it is often absurdly called, the binomial 

 system. That we must have a technical system of nomen- 

 clatare I suppose no one here will dispute. It is not, how- 

 ever, always admitted by popular writers who have not 

 appreciated the difficulty of the matter, and who think all 

 names should be in the vernacular. There is the obvious 

 difficulty that the vast majority of plants do not possess vernac- 

 ular names, and the attempts to manufacture them in a 

 popular shape have met with bat little success. Then, from 

 lack of discriminatiug power on the part of those who use 

 them, vernacular names are often ambiguous; thus Bullrush 

 is applied equally to Typha and to Scirpus, plants extremely 

 different. Vernacular names, again, are only of local utility, 

 while the Linnean system is intelligible throughout the 

 world. 



A technical name, then, for a plant or animal is a necessity, 

 as without it we cannot fix the object of our investigations 

 into its affinity, structure or properties, 'Nomina si nescis 

 perit et cognitio rerum.'^s 



i&Liun. Phil, 210. 



