My dear Hooker

Drege contains no materials for seeing range of genera, so I return it by Deliverance Co^y., & I hope you will get it safe by Thursday night or Friday morning.—²

I now want to ask your opinion & for facts on a point; & as I shall often want to do this during next year or two; so let me say once for all, that you must not take trouble out of mere goodnature (of which towards me you have a most abundant stock) but you must consider, in regard to trouble any question may take, whether you think it worth while, (as all loss of time so far lessens your original work) to give me facts to be quoted on your authority in my work. Do not think I shall be disappointed if you cannot spare time; for already I have profited enormously from your judgment & knowledge.— I earnestly beg you to act as I suggest, & not take trouble solely out of goodnature.—

My point is as follows—Harvey gives cases of Fucus varying remarkably, & yet in same way under most different conditions. D. Don makes same remark in regard to Juncus bufonius in England & India.— Polygala vulgaris has white red & blue flowers in Faröe, England, & I think Herbert says in Zante.³

Now such cases seem to me very striking, as showing how little relation some variations have to climatal conditions.

Do you think there are many such cases? Does Oxalis corniculata present exactly same varieties under very different climates?

How is it with any other British plants in N. Zealand, or at foot of Himalaya?— Will you think over this & let me hear result.—⁴

One other question; do you remember, whether the introduced Sonchus in N. Zealand, was less, equally, or more common than the aboriginal stock of same species, where both occurred together: I forget whether there is any other case parallel with this curious one of the Sonchus.—

My wife starts with Etty on Thursday for Hastings: she is no better.—⁵

I have been making good, though slow, progress with my Book, for facts have been falling nicely into groups, enlightening each other.—

My dear Hooker | Farewell | C. Darwin