TO J.D.HOOKER.

Down, November 14th [1857].
On Tuesday I will send off from London, whither I go on that day, Ledebour's three remaining volumes, Grisebach and Cybele, i.e., all that I have, and most truly am I obliged to you for them.

I find the rule, as yet, of the species varying most in the large genera universal, except in Miquel's very brief and therefore imperfect list of the Holland flora, which makes me very anxious to tabulate a fuller flora of Holland.

I shall remain in London till Friday morning, and if quite convenient to send me two volumes of D.C.Prodromus, I could take them home and tabulate them.

I should think a volume with a large best known natural family, and a volume with several small broken families would be best, always supposing that the varieties are conspicuously marked in both.