Thus, with respect to intermediate varieties being rare, I found it put, as I suspected, much too strongly (without the limitations and doubts which you point out) by a very good naturalist, Mr.Wollaston, in regard to insects; and if it could be established as true it would, I think, be a curious point.
Your answer in regard to the introduced plants not being particularly variable, agrees with an answer which Mr.H.C.Watson has sent me in regard to British agrarian plants, or such (whether or no naturalised) [as] are now found only in cultivated land.

It seems to me very odd, without any theoretical notions of any kind, that such plants should not be variable; but the evidence seems against it.
Very sincere thanks for your kind invitation to the United States: in truth there is nothing which I should enjoy more; but my health is not, and will, I suppose, never be strong enough, except for the quietest routine life in the country.

I shall be particularly glad of the sheets of your paper on geographical distribution; but it really is unlikely in the highest degree that I could make any suggestions.
With respect to my remark that I supposed that there were but few plants common to Europe and the United States, not ranging to the Arctic regions; it was founded on vague grounds, and partly on range of animals.

But I took H.C.

Watson's remarks (1835) and in the table at the end I found that out of 499 plants believed to be common to the Old and New World, only 110 did not range on either side of the Atlantic up to the Arctic region.