My dear Lindley

Will you allow me once again to trespass on your kindness? I send in little Box by this post with a flower of a Dendrobium sent me from Kew as D. macrophyllum;² but it was previously sent me by an orchid grower as D. chrysanthum & is the one I asked you about. Can you tell me which it is?—

Since I wrote I have been working hard in tracing spiral ducts; & I find in all cases that the sides of the Labellum receive all their ducts from the two antero-lateral bundles of the ovarium, which bundles supply the 2 lower sepals & 2 stigmas (the rostellum being supplied from the posterior bundle which supplies the fertile anther & upper sepal)

You & Brown believe the Labellum is compound when it presents ridges &c;³ but Hooker tells me he thinks I am right in inferring from the above facts that the Labellum is always an organ compounded of lower petal & 2 anthers, of outer whorl, with doubtful traces of one anther, of inner whorl.

Now this is a long preface to asking you whether the Orchid (name forgotten) which has Labellum quite similar to the two upper petals be very rare; & if not & you can spare a single dried flower; for I am very curious to try & trace its ducts or spiral vessels. I believe you somewhere speak of Orchid with medial spike or projection on Labellum; this would give me a good chance of tracing the one bundle of ducts which out of the 15 I have failed to discover clearly & trace.—

Forgive me, if you can, for being so troublesome & believe me

Your’s sincerely obliged | Charles Darwin