My dear F.

If in the collection there are specimens of Desmodium gyrans from different districts, observe whether the little lateral leaflets differ in size on full-grown leaves.¹ Look out for any abnormal projection at apex of leaflet, though excessively improbable— or for the abortion of the blade alone.—

In my living specimens—some of the leaves have 2 leaflets, some one & some none. The 2 little leaflets either stand exactly opposite each other or not so. How are these points with plants in a state of nature?

I have a wild hypothesis that the little leaflets may be tendrils reconverted into leaflets, as I believe to be the case with the grass-like leaves of Lathyrus nissolia & almost certainly with the little stipule-like projection at the end of the leaf of the common Bean.—Vicia faba.²

Your affect | C. Darwin

P.S. | Thank Sanderson cordially for his most kind assistance.— The Hæmoglobin was at first very dark red-brown; I sh^d be very glad to know whether it is meta-hæmoglobin.—³