456 LETTEBS TO DARWIN, 1843-1859 
quite sure I should. The object of these books, you must 
remember, is not to tell everything about a plant, and 
perhaps least of all to tell the amount of their variation, but 
to lead others to : — 1st, name; 2, affinities; 3, distribution; 
4, uses — and so on. As a rule the amount of variation is 
a speciality affecting the species differently in different 
locahties, and is therefore only recorded when the omission 
of its record might lead to the non-recognition of the plant 
by the character. All plants are variable : see how the 
descriptions teem with ' vel,' ' aut,' ' et,' &c. 
The long and short of the matter is, that Botanists do 
not attach that definite importance to varieties that you 
suppose ; they do not treat large and small genera equally 
and similarly, and the sum of inequalities thus produced 
tends to make the species of small genera look more invariable 
than big. 
Had I been doing the Flora Indica as I should have 
done with an eye to making it a descriptive book of variation, 
I should most certainly have added varieties to most of the 
small genera, thus — 
Naraveha a and b, Ceratocephalus a, h, c, d, 
Adonis a, h, c, Caltha a, h, c, d, 
Calhanthemum a, h, Isopyrum a, h, c, 
Aquilegia a-z, 
to render them equivalent to the varieties in Clematis and 
other big genera, and confounded your statistics. 
Just look and see how much more frequently we notice 
under the monotypic genera, its variations and variability, 
than we do in the polytypic (excuse the coined phrase). 
So my dear Darwin do not be in a hurry with your con- 
clusions. I am quite sure that had monotypic genera or 
oligotypic been at all materially less variable than polytypic 
it would not have escaped the sagacity of men like Linnaeus, 
Brown, D. C, or Bentham, and that it would force itself 
on the attention of any cautious observer. 
March 18, 1858. 
You have set me thinking much on varieties in great 
versus small genera. I am obstinately inclined to take 
general monographs for data in preference to local Floras, 
for the general works alone seem to me to give a fair chance 
