In this latter way I believe crossing is all-important, and now for twenty years I have been working at flowers and insects under this point of view. I do not like Hooker's terms, centripetal and centrifugal (80/2. Hooker's "Introductory Essay to the Flora of Tasmania," pages viii. and ix.): they remind me of Forbes' bad term of Polarity. (80/3. Forbes, "On the Manifestation of Polarity in the Distribution of Organised Beings in Time."--"R. Institution Proc." I., 1851-54.)英文原著 · 《More Letters of Charles Darwin Volume I》
I am glad to hear what you say about parallelism: I am an utter disbeliever of any parallelism more than mere accident. It is very strange, but I think Forbes is often rather fanciful; his "Polarity" (36/2. See Letter 41, Note.) makes me sick--it is like "magnetism" turning a table.英文原著 · 《More Letters of Charles Darwin Volume I》
While the polarity of the prickly lettuce leaves is by no means so marked, Dr. Gray's theory about the rosin-weed may be applied to them as well.英文原著 · 《WILD FLOWERS》