To Max Ernst Wichura 3 February 1
Down, Bromley, Kent
Dear & Respected Sir
From continued ill-health & other reasons I have only recently finished reading your work on Hybrid Willows, & I did not wish to thank you for your very kind present until I had read it.2 Your work has greatly interested me in many ways. The extreme frequency of Hybrid Willows is quite a new fact to me & your explanation of their numbers on certain spots is remarkably ingenious.3 I was also very glad to read your account of the development of pollen-grains in hybrids.4 I see you doubt Gärtner’s statements about reversion or Rückschäge;5 on the other hand I observe that Naudin wishes to make it a general law that all Hybrids quickly revert to either parent form;6 I suspect this great difference in your & Naudin’s conclusions is that he has worked on cultivated varieties & you on wild forms.7 You will find in the Chapter on Hybridism in the “Origin of Species,” the view that Hybrids are sterile from not being perfectly accommodated to their conditions of life, briefly given;8 but I have lately made observations which cause me to doubt in some degree the truth of this view.9 I have been much interested & gratified by the remarks which you make towards the close of your volume on my views with respect to Species.10
With sincere respect I beg leave to remain, Dear Sir, Yours faithfully & obliged | Charles Darwin
He has finished MEW’s work on hybrid willows [Die Bastardbefruchtung im Planzenreich (1865)] and sends his thanks. The extreme frequency of hybrid willows is new to CD, and he finds the explanation of their numbers in certain locations ingenious.
Comments on the criticism of Gärtner’s view of reversion
and the differences between MEW and Naudin.
CD now has doubts regarding his own view that hybrids are sterile from not being perfectly accommodated to their conditions of life.
Please cite as
Darwin Correspondence Project, “Letter no. 4765A,” accessed on 28 October 2016, http://www.darwinproject.ac.uk/DCP-LETT-4765A