TO J.D.HOOKER.

[November] 1844.
...What a curious, wonderful case is that of the Lycopodium! (14/1.

Sir J.D.Hooker wrote, November 8, 1844: "I am firmly convinced (but not enough to print it) that L.Selago varies in Van Diemen's Land into L.
varium.

Two more different SPECIES (as they have hitherto been thought), per se cannot be conceived, but nowhere else do they vary into one another, nor does Selago vary at all in England.")...I suppose you would hardly have expected them to be more varying than a phanerogamic plant.
I trust you will work the case out, and, even if unsupported, publish it, for you can surely do this with due caution.

I have heard of some analogous facts, though on the smallest scale, in certain insects being more variable in one district than in another, and I think the same holds with some land-shells.