Chapter 261

(605/2. The following letter is of interest because it relates to one of the two chief difficulties Darwin met with in working out the morphology of the orchid flower. In the orchid book (605/3. Edition I., page 303.) he wrote, "This anomaly [in Habenaria] is so far of importance, as it throws some doubt on the view which I have taken of the labellum being always an organ compounded of one petal and two petaloid stamens." That is to say, it leaves it open for a critic to assert that the vessels which enter the sides of the labellum are lateral vessels of the petal and do not necessarily represent petaloid stamens. In the sequel he gives a satisfactory answer to the supposed objector.)

Down, November 10th, [1861].

For the love of God help me. I believe all my work (about a fortnight) is useless. Look at this accursed diagram (Figure 9) of the butterfly-orchis [Habenaria], which I examined after writing to you yesterday, when I thought all my work done. Some of the ducts of the upper sepal (605/4. These would be described by modern morphologists as lower, not upper, sepals, etc. Darwin was aware that he used these terms incorrectly.) and upper petal run to the wrong bundles on the column. I have seen no such case.

This case apparently shows that not the least reliance can be placed on the course of ducts. I am sure of my facts.

There is great adhesion and extreme displacement of parts where the organs spring from the top of the ovarium. Asa Gray says ducts are very early developed, and it seems to me wonderful that they should pursue this course. It may be said that the lateral ducts in the labellum running into the antero-lateral ovarian bundle is no argument that the labellum consists of three organs blended together.

In desperation (and from the curious way the base of upper petals are soldered at basal edges) I fancied the real form of upper sepal, upper petal and lower sepal might be as represented by red lines, and that there had been an incredible amount of splitting of sepals and petals and subsequent fusion.

This seems a monstrous notion, but I have just looked at Bauer's drawing of allied Bonatea, and there is a degree of lobing of petals and sepals which would account for anything.

Now could you spare me a dry flower out of your Herbarium of Bonatea speciosa (605/5. See "Fertilisation of Orchids," Edition I., page 304 (note), where the resemblances between the anomalous vessels of Bonatea and Habenaria are described. On November 14th, 1861, he wrote to Sir Joseph: "You are a true friend in need. I can hardly bear to let the Bonatea soak long enough."), that I might soak and look for ducts. If I cannot explain the case of Habenaria all my work is smashed. I was a fool ever to touch orchids.