Dear and respected Sir

I must beg your pardon that I have not answered your very kind letter before this, but I was waiting for my paper on Orchids being printed in the Botanische Zeitung to send you a copy;¹ I hope that I shall be able to do it in the next days, you will see that it does not contain much more as you know as yet from my last letter.² And now let me thank you that you have taken so much pain to get my paper printed, I have seen it in the Annals and Mag. of n. hist. and was very glad of it; I feel very much obliged to you.³ I am glad being able to do you a service in publishing my experiments on Linum and Primula, but I can speak only about L. perenne and P. sinensis, beacause my experiments on P. officinalis and elatior were destroyed by childeren in the botanical garden.⁴ On Linum I spoke a few words on the meeting of German naturalists in Stettin.⁵

In your paper on Primula you say, that you never placed pollen of the same flower on its own stigma⁶ but I thought this manner of fertilisation to be of interest too, and I had in this way six unions instead of your four. The result was that the two heteromorphic unions gave most seeds, namely each capsule 43 good seeds on an average; the two homomorphic unions, if the flowers were crossed, gave 18 seeds on an average per capsule, the flowers selffertilised only 13. In the first four unions I got good capsules of every fertilised flower, only in the last two I did not always succeed in the fertilisation.— You see that, though I have counted the seeds, not weighed, I have come to the same results as you.⁷ But I must say that I cannot agree with you about the pollen of P. sinensis, for I found the pollen grains of the long styled form almost in the same manner differing from that of the short styled as in P. officinalis and elatior; between the small transparent grains of the short-styled form there were only a few of larger seize and opace.—⁸

Perhaps it will interest you to hear that I have made other experiments to answer the question to what form the descendants of the two forms belong. From seeds that I had got last year by your four unions I got about 60 young plants and these were the interesting results: Of the descendants from long-styled plants fertilised with their own form pollen most, but not all, were again long styled; the short-styled form fertilised with its own-form pollen produced in the greatest part short styled plants; if the short styled form was fertilised with the long-styled or the long styled with the short styled nearly the half of the young plants was short-styled the other half long-styled.—⁹

Coming to a close I must say that if there is anything, where I can serve you, perhaps with microscopical researches, I should be very glad if you would tell me about it, the winter especially leaves me a great deal of time.

Professor Treviranus wanted me to send you his respects and remembrances.¹⁰ Some time ago I heard that you were not quite well but I hope that this letter will find you in good health and I remain most respected Sir | yours | sincerely | Hildebrand