INTRODUCTION. 
so far as in me lies and the power of study can avail, I have done 
my best to ascertain these ultimate names, once and for all, and 
put them into the hands of all such as desire correctness and the 
avoidance of expensive delusions. In many of the more critical 
cases, indeed, the valid authority is quoted ; in some, also the date 
at which the prevalent specific was imposed. Nor have I been 
at less pains to cope with synonymy : it is a very common thing 
in catalogues to find two or three names quoted, that all cover one 
species. Even such compilations as M. Correvon’s are not inno- 
cent of this fault; and much care and research are accordingly 
necessary here, among the recognised authorities, to achieve a 
helpful guide as to what is a true species, what a variety, and what 
a mere discarded synonym. 
In the matter of genera, however, the case is different. No 
botanist has it in his power to alter an authorised specific name : 
all botanists of repute have a perfect right to redistribute races 
at their pleasure. And this is a vagary with which it is impos- 
sible finally to cope. Silene, for instance, is now, by modern 
botanical fashion, made to hand over S. Hlizabethae into the 
house of Melandryum, and S. Pumilio into that of Saponaria. 
All that such a book as this (or any other) can do, is to suggest 
the tendency of recent botany, so that the innocent may not 
some day be seduced by some catalogue’s flaming proclamation, 
as a “novelty,” of Melandryum Elizabethae or Saponaria Pumilio. 
The earnest, however, must always keep on guard, for new races 
are still being carved out of old, or submerged. Paoli and 
Fioretti, for instance, sink Oxytropis into Astragalus; while 
when it comes to American botany, the brain reels before the 
minute and subtle class-distinctions into which patriotic pride 
has now mangled Aster and Oenothera. This book, like panting 
Time, has toiled after these eager botanists,—but not wholly, I 
shall hope, in vain; for, though I have usually not recognised 
these transatlantic minutiae, the names of such new-made families 
are quoted in their place, so that the anxious inquirer after 
Wyomingia or Lavauxia will find, on reference, that his quest 
brings him to nothing newer than Aster and Oenothera. More 
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