To Daniel Oliver 20 [February 1863]1
Down Bromley Kent
20th Friday Night.
Many thanks about Phyllotaxy. Your cases seem sufficient & when next in London, I shall hear what Falconer has to say.2 Do not look for any more cases; but if you shd. stumble on them, please let me hear. I find the subject very difficult to understand; indeed I cannot understand several most simple points, such as whether there is ever more than one spire; but when Hooker comes he may be able to enlighten me.3 I must learn the elements to understand force of Falconer’s objections: he considered the laws as fixed as that of the attraction of gravity!—
I see what Treviranus says about Primula longiflora;4 I shd. like to know (if you are up in Primula) whether this species is closely allied to P. Scotica; because Mr J. Scott of Bot. Garden of Edinburgh, has been carefully observing Primulas (& I feel a conviction that he is trust-worthy) & he says P. Scotica is never dimorphic, & is much surprised, as he says it is so like P. farinosa: he has sent me plants of both, but they look very sickly.5
By the way I see Mr Bentham makes P. Scotica var. of P. farinosa;6 would it not be worth while to tell him of Mr Scotts observation;7 for there can be no doubt that this difference indicates an important functional difference. Unless indeed P. farinosa presents 3 sexual forms; but then they all three would grow together.
Treviranus in his Review of the Orchids8 does not seem to appreciate at all the prettiness of the adaptations, which seems to me the cream of the case.
Yours very sincerely | Ch. Darwin
Having trouble understanding laws of phyllotaxy in order to grasp Hugh Falconer’s objections.
L. C. Treviranus on Primula [see 3980] misses the "prettiness" of the adaptations.
John Scott says P. scotica is never dimorphic.