If there had been a large infusion of different people in Egypt, and if they had exterminated the old race, do you not suppose this would have established itself, perpetuated itself, and that its particular adaptations to the climate would have been different from that of the present race?
If you cut off all future immigration into North America, would the Indians resume possession of the country? or else our descendants become a copper-colored race?
Enough for the present. When you have cracked these nuts, send me, if you please, another sheet.
Ever yours cordially,
Asa Gray.
Cambridge, July 6, 1863.
Dear Brace,—Yours of 20th ult. came just as J. was off for New Haven and I getting ready to go to her aid.
We came back only on Thursday, or rather Friday morning. My hands so full that I could not write to Darwin, to whom I owe a long letter, till to-night. I will now inclose your note.
It would be very like a chemist to think that external influences will explain everything. But I presume he believes that peculiarities are heritable. If he does, then he thinks he can explain, or will be able to explain, the origination of variations. I cannot, that is, to any extent, and do not expect to. When he will show us how external influences actually worked to change a peach into a nectarine, I will consider his proposition.
If he means by “external influences” whatever has brought about the change, very well. I, of course, allow that every variation has a cause, a physical cause. But it seems to me you may as well say that conception and the production of a normal offspring is the result of “external influences” as the production of an abnormal (variant) offspring.
But there is no use writing at random.