As our readers know, fir trees have been erroneously called Picea, and spruces, Abies; the error originating in England. Spruces have always been correctly called Picea, and the firs Abies on the Continent of Europe. Dr. Engelmann has, however, pointed out that botany would cease to be a science unless conformed to recognized rules of nomenclature, which is that a prior name must prevail. In America we have adopted the first course, and the best English authorities have also assented to its propriety; but the following answer to a correspondent in the Gardener's Chronicle shows that the error will not be buried without a struggle:

"Abies, or Picea: R.~No doubt the change is inconvenient, but you can obviate it by speaking of 'silvers' or 'Spruces.' Again, in most cases every one would know what was meant if you simply used the specific name, such as no-bilis, ajanensis, Nordmanniana, etc. We do not see why Englishmen should be isolated from the rest of the world to the general confusion; still less do we subscribe to the notion that it is their duty to perpetuate an error which other people have corrected".