By the Hon. and Rev. William Herbert. 23 



very variable. Rhododendron and Azalea belong to two 

 classes, widely separated by the number of the anthers, 

 which is the characteristic feature of those classes ; yet they 

 are found to breed so freely together, and accord so exactly 

 in the seed and capsule, that it can scarcely be doubted that 

 they have branched from one original stock. Indeed, the 

 Azalea is reported to have been occasionally seen with ten 

 anthers, instead of five. At the same time, I doubt the possi- 

 bility of intermixing the Alpine Rhododendrons with those of 

 Pontus, India, and America, although united in one genus. 



The most distinguished Botanists are perpetually at vari- 

 ance with each other, as to the subdivisions of the vegetable 

 system ; nor has any precise meaning been affixed to the 

 terms by which they are known, as a guide to their labours ; 

 and, if we ask what is an Order ? What is a Genus ? What is 

 a Species ? What is a Variety ? We shall find the answers 

 very unsatisfactory. The most rational interpretation of the 

 terms, I think, will be found as follows : An Order, — all the 

 genera or original stocks which have general affinities to 

 each other, though not such as to warrant a belief that they 

 have branched from one stock. A Genus, all the species 

 which have peculiar affinities, distinguishing them from all 

 others; and which, I think, render it probable that they 

 have branched, since the creation of the world, from one ori- 

 ginal. A Species,— a race of plants that will, in the present 

 state of the world, perpetuate itself without varying in essen- 

 tial particulars, so as to confound itself with any other. A 

 permanent or local Variety,— that which will perpetuate itself in 

 a particular form, if kept in its native soil or situation, or at 

 a distance from all other varieties ; but which would, other- 



