In correspondence Darwin continued to discuss his species work with Hooker, and he took it personally when Hooker remarked of another naturalist "that no one has hardly a right to examine the question of species who has not minutely described many." However, even Richard Owen who was opposed to any mutability in species had told him it was "a very fair subject" with a mass of facts to be investigated, "& though I shall get more kicks than half-pennies, I will, life serving, attempt my work." Early in November Darwin, hinting that "geographical distrib: will be the key which will unlock the mystery of species", invited Hooker to "look over a rough sketch (well copied) on this subject" while fearing this was "too impudent a request".