These observations will equally apply in the case of all genera of which there are several names given as species in the catalogues. Amid so much confusion, it is not to be wondered at that the gardener is puzzled to find out the difference between species and varieties; and that he is, in consequence of this feeling, deterred from the study of trees and shrubs, and consequently from recommending his employer to plant a collection of them, or even to introduce a greater variety into his pleasure-ground or plantations than is given by the common routine kinds. Let him, however, cease to puzzle himself by endeavours to find out specific distinctions where none exist; and let him rely upon this, that wherever a species is truly distinct, that distinction will be so obvious to the eye of a practised observer as to dispel all doubts. The distinction between varieties is equally clear: but there are certain persons, both among cultivators and practical botanists, who are continually in search of new species or varieties, and these readily seize upon the slightest marks indicating a difference, though this difference very often refers merely to one individual plant as compared with another individual plant; and we all know that differences of this kind may exist in a very striking degree, without there being any distinction between the plants sufficiently marked to constitute either a species or a variety.
