LETTER 739. TO W. THISELTON-DYER. Down, July 22nd [1877].

Many thanks for seeds of the Malva and information about Averrhoa, which I perceived was sensitive, as A. carambola is said to be; and about Mimosa sensitiva. The log-wood [Haematoxylon] has interested me much. The wax is very easily removed, especially from the older leaves, and I found after squirting on the leaves with water at 95 deg, all the older leaves became coated, after forty-eight hours, in an astonishing manner with a black Uredo, so that they looked as if sprinkled with soot and water. But not one of the younger leaves was affected. This has set me to work to see whether the "bloom" is not a protection against parasites. As soon as I have ascertained a little more about the case (and generally I am quite wrong at first) I will ask whether I could have a very small plant, which should never be syringed with water above 60 deg, and then I suspect the leaves would not be spotted, as were the older ones on the plant, when it arrived from Kew, but nothing like what they were after my squirting.

In an old note of yours (which I have just found) you say that you have a sensitive Schrankia: could this be lent me?

I have had lent me a young Coral-tree (Erythrina), which is very sickly, yet shows odd sleep movements. I suppose I could buy one, but Hooker told me first to ask you for anything.

Lastly, have you any seaside plants with bloom? I find that drops of sea-water corrode sea-kale if bloom is removed; also the var. littorum of Triticum repens. (By the way, my plants of the latter, grown in pots here, are now throwing up long flexible green blades, and it is very odd to see, ON THE SAME CULM, the rigid grey bloom-covered blades and the green flexible ones.) Cabbages, ill-luck to them, do not seem to be hurt by salt water. Hooker formerly told me that Salsola kali, a var. of Salicornia, one species of Suaeda, Euphorbia peplis, Lathyrus maritimus, Eryngium maritimum, were all glaucous and seaside plants. It is very improbable that you have any of these or of foreigners with the same attributes.

God forgive me: I hope that I have not bored you greatly.

By all the rules of right the leaves of the logwood ought to move (as if partially going to sleep) when syringed with tepid water. The leaves of my little plant do not move at all, and it occurs to me as possible, though very improbable, that it would be different with a larger plant with perhaps larger leaves. Would you some day get a gardener to syringe violently, with water kept in a hothouse, a branch on one of your largest logwood plants and observe [whether?] leaves move together towards the apex of leaf?

By the way, what astonishing nonsense Mr. Andrew Murray has been writing about leaves and carbonic acid! I like to see a man behaving consistently...

What a lot I have scribbled to you!

(FIGURE 13. Leaf of Trifolium resupinatum (from a drawing by Miss Pertz).)