few protean genera & Carex from its unusual size) 1005 sp. in genera of 5 & upwards, & 917 in genera 
with 4 & downwards; & the large genera have 881000 varieties & the small genera only 501000. This 
rule seems to be general. & Hooker is going to work out some Floras on same plan.— But to my disgust 
your vars. marked by big-type are only in proportion 481000 to 461000. 
Several things have made me confidently believe that "close" species occurred most frequently in the 
larger genera; & you may remember that you made me the enclosed list. Now to my utter disgust, I find 
that the case is somewhat the reverse of what I had so confidently expected, the close species hugging 
the smaller genera. Hence I have enclosed the list. & beg you kindly to run your eye over it, & see 
whether, not understanding my motive, you cd have attended more to the small than to the large 
genera: but I can see that this is not probable. And do not think that I want you to "cook" the results for 
me.— Are the close species very generally geographical representative species: this might make some 
difference? 
Lately I examined buds of Kidney Bean with pollen shed, but I was led to believe that the pollen cd 
hardly get on stigma by wind or otherwise, except by Bees visiting & moving the wing petals: hence I 
included a small bunch of flowers in two Bottles, in everyway treated the same: the flowers in one I daily 
just momentarily moved as if by a Bee; these set 3 fine pods, the other not one. Of course this little 
experiment must be tried again, & this year in England it is too late, as the flowers seem now seldom to 
set. If Bees are necessary to this flower's self-fertilisation. Bees must almost cross them, as their dusted 
right-side of head & right legs constantly touch the stigma. 
I have, also, lately been reobserving daily Lobelia fulgens— this in my garden is never visited by insects 
& never sets seeds, without pollen be put on stigma, (whereas the small blue Lobelia is visited by Bees & 
does set seed); I mention this because these are such beautiful contrivances to prevent the stigma ever 
getting its own pollen; which seems only explicable on the doctrine of the advantage of crosses. 
I forget whether I ever said I had received safely Mr Watson's papers. & your Lesson in Botany, for 
which very many thanks & which I am now reading. But I have never had the last part of your paper on 
Naturalised Plants. If you have a spare copy (which is not likely) I shd be very glad of it: otherwise I will 
borrow Hooker's. I ought to feel ashamed of the length of this letter, knowing how busy you are. 
My dear Dr Gray 
Believe me with much 
sincerity Your's truly 
C. Darwin 
I will try if I can anyhow get seed of the Adlumia cirrhosa & observe it next summer. Perhaps they have it 
at Kew. 
