I received this morning Masdevallia, which is very curious, but I cannot understand it,¹ & Cypripedium, whose ducts I will attack tomorrow. (N.B I find strong Nitric Acid most useful)²    Your labours are over; & most truly do I thank you. No, your labours are not quite over, if you can just try irritability of Bolbophyllum rhizophora (spelling?).—³

I have read papers on Catasetum, which do not shake me, but make me extremely anxious for the other plant.—⁴

I have made out the missing bundle of ducts proceeding from the anterior ovarian bundle: I might have looked for ever to Labellum; & I was so prepossessed by Brown’s & Lindley’s view that it was a chance I ever found it.⁵ The enclosed gives structure of every orchid yet looked at. The missing bundle is attached to front of column, running up to beneath stigmatic cavity— So from what you say I hope I may look at homologies of Orchids as pretty safe.— I shall be curious when I get Bot. Zeitung to see what Link says on vessels of column.—⁶ Farewell, with hearty thanks for all your never ending assistance.

Your affect | C. Darwin

I have sent my paper on dimorphism in Primula to Linn. Soc. I shall go up, & read it, whenever it comes on (on 21^st Nov.); I hope you may be able to attend, for I do not suppose many will care a penny for the subject.—⁷