From William Marshall to Horace Darwin [7 July 1873]

Dear Bounder

I thought it w^d. not suit you but might be worth while letting you know. I am glad you are well, & you seem to be doing the right thing.

I am quite convinced that nothing is so important for y^r. health as getting work t^t. you realy like, & doing a good deal of it.

Pinckney has apparently settled to sign articles & stay here.

I have been reduced to a deplorable state of idiotsy by face & toothache wither the annexed production—- | b

Begin here.

A friend of mine, who is inclined to be sceptic, called on me the other day & asked me how many Grandfathers I had! I replied "two of course" "& how many great grandfathers?"— "4" I said after a faint pause.

"And how many g^t. g^t. grandfathers?"— "8" I replied at once having now mastered the principal "And how many g^t. g^t. g^t. grandfathers?"

"16" I said somewhat appaled at the rapid increase— "And yet" he said "you had only one Adam" .and he left me sadly.

On thinking this over it did seem rather odd. but perhaps, it struck me, several of my ancestors married their first cousins.

Well if one of my g^t. grandfathers married a first cousin t^t. only reduces the n^o. of my g^t. g^t. g^t. grandfathers from 16 to 15.— no material decrease when it is considered that they double with every generation.

This looked bad.

Some of 'em must have married their sisters!! Shocking as the thought is, in the earliest times they can't well have helped it.

There must then have been a good deal of breeding in. It is rather difficult anyhow, & I think I c^d. believe in several Adams easier than in one—

one seems hardly enough.

Has Galton written any book on S. Africans? if so w^h. is its title & price, & is it good. I have been reading ab^t. the Africans lately and find they interest me.