LOCAL FLORAS AND VARIETIES 457 
of the species being uniformly treated, because local Floras 
consist of : 1. Local plants — ^these we agree are not so 
variable as mundane plants. 
2. Mundane plants, of which only one form is found in 
the said local area, and which are hence not treated as 
variable in the Flora of that area. 
3. Mundane plants, of which two or more varieties are 
found in the area. 
Now as you increase your area the small local (i.e. in- 
variable) genera do not reappear, but the small mundane 
genera do with an increased number of variations, and 
the large mundane genera with their variable species also 
relatively increase. Is this not so ? Be that as it may, 
I have just got Weddell's monograph of Urticeae back 
from binder, and as I told you that I thought it would 
prove as unexceptional food for analysis as may be, I 
have roughly tabulated the results and enclose them. 
Weddell has reduced both the large and small genera 
enormously and consistently, and I attach the greater 
confidence to his work from the close accordance between 
the relative number of species to variation in large and 
small genera. 
Again, if the species of small local genera are themselves 
local, it follows that we procure fewer specimens of the 
species of such genera than of large, and hence make fewer 
varieties. This any general Herbarium shows. A genus of 
one species presents only a single specimen much oftener 
than a genus of 10 species does only 10 specimens. 
Again, suppose I am naming by comparison or otherwise 
a species of a large genus, I find it agrees a Httle with many 
species, exactly with none, but most nearly one — I hesitate 
and am in difficulty and my tendency is to make a var. of 
that it is nearest, all the more if the latter is itself variable ; 
but in naming in the same way a species of a small genus I 
find no such difficulty — it is perhaps not exactly Hke the 
species to which I refer it, still it is not the least like any tiling 
else. So I made a var. of my first plant partly lest my 
successor should refer it to any of the other species which 
it resembled from missing it under the vars. of that I 
refer it to, but in the second case no such precaution is 
necessary. 
