If you feel any interest, or can get any one else to feel any interest on the aberrant genera question, I should think the most interesting way would be to take aberrant genera in any great natural family, and test the average number of species to the genera in that family.
How I wish we lived near each other! I should so like a talk with you on geographical distribution, taken in its greatest features.

I have been trying from land productions to take a very general view of the world, and I should so like to see how far it agrees with plants.
LETTER 42.

TO MRS.

LYELL.
(42/1.

Mrs.Lyell is a daughter of the late Mr.Leonard Horner, and widow of Lieut.-Col.