f carrying on our work; and of these you rank as
the first.

With cordial good wishes for your success in all your work and for your
happiness.

LETTER 249. TO E. RAY LANKESTER. Down, April 15th [1872].

Very many thanks for your kind consideration. The correspondence was in
the "Athenaeum." I got some mathematician to make the calculation, and
he blundered and caused me much shame. I send scrap of proofs from last
edition of the "Origin," with the calculation corrected. What grand work
you did at Naples! I can clearly see that you will some day become our
first star in Natural History.

(249/1. Here follows the extract from the "Origin," sixth edition, page
51: "The elephant is reckoned the slowest breeder of all known animals,
and I have taken some pains to estimate its probable minimum rate of
natural increase. It will be safest to assume that it begins breeding
when thirty years old, and goes on breeding till ninety years old,
bringing forth six young in the interval, and surviving till one hundred
years old; if this be so, after a period of from 740 to 750 years, there
would be nearly nineteen million elephants alive, descended from the
first pair." In the fifth edition, page 75, the passage runs: "If this
be so, at the end of the fifth century, there would be alive fifteen
million elephants, descended from the first pair" (see "Athenaeum," June
5, July 3, 17, 24, 1869).)

LETTER 250. TO C. LYELL. Down, May 10th [1872].

I received yesterday morning your present of that work to which I, for
one, as well as so many others, owe a debt of gratitude never to be
forgotten. I have read with the greatest interest all the special
additions; and I wish with all my heart that I had the strength and
time to read again every word of the whole book. (250/1. "Principles of
Geology," Edition XII., 1875.) I do not agree with all your criticisms
on Natural Selection, nor do I suppose that you would expect me to do
so. We must be content to differ on several points. I differ must about
your difficulty (page 496) (250/2. In Chapter XLIII. Lyell treats
of "Man considered with reference to his Origin and Geographical
Distribution." He criticizes the view that Natural Selection is capable
of bringing about any amount of change provided a series of minute
transitional steps can be pointed out. "But in reality," he writes, "it
cannot be said that we obtain any insight into the nature of the forces
by which a higher grade of org