that I enjoy exceedingly writing to you, and that your answers are of the
greatest possible service to me. I return with many thanks the proof on
Aquilegia (43/1. This seems to refer to the discussion on the genus
Aquilegia in Hooker and Thomson's "Flora Indica," 1855, Volume I.,
Systematic Part, page 44. The authors' conclusion is that "all the
European and many of the Siberian forms generally recognised belong to one
very variable species." With regard to cirripedes, Mr. Darwin spoke of
"certain just perceptible differences which blend together and constitute
varieties and not species" ("Life and Letters," I., page 379).): it has
interested me much. It is exactly like my barnacles; but for my particular
purpose, most unfortunately, both Kolreuter and Gartner have worked chiefly
on A. vulgaris and canadensis and atro-purpurea, and these are just the
species that you seem not to have studied. N.B. Why do you not let me buy
the Indian Flora? You are too magnificent.

Now for a short ride on my chief (at present) hobbyhorse, viz. aberrant
genera. What you say under your remarks on Lepidodendron seems just the
case that I want, to give some sort of evidence of what we both believe in,
viz. how groups came to be anomalous or aberrant; and I think some sort of
proof is required, for I do not believe very many naturalists would at all
admit our view.

Thank you for the caution on large anomalous genera first catching
attention. I do not quite agree with your "grave objection to the whole
process," which is "that if you multiply the anomalous species by 100, and
divide the normal by the same, you will then reverse the names..." For, to
take an example, Ornithorhynchus and Echidna would not be less aberrant if
each had a dozen (I do not say 100, because we have no such cases in the
animal kingdom) species instead of one. What would really make these two
genera less anomalous would be the creation of many genera and sub-families