And Sir Joseph did far more than supply knowledge and guidance in technical matters: Darwin owed to him a sympathetic and inspiriting comradeship which cheered and refreshed him to the end of his life.
A sentence from a letter to Hooker written in 1845 shows, quite as well as more serious utterances, how quickly the acquaintance grew into friendship.
"Farewell! What a good thing is community of tastes! I feel as if I had known you for fifty years.

Adios." And in illustration of the permanence of the sympathetic bond between them, we quote a letter of 1881 written forty-two years after the first meeting with Sir Joseph in Trafalgar Square (see "Life and Letters," II., page 19).

Mr.Darwin wrote: "Your letter has cheered me, and the world does not look a quarter so black this morning as it did when I wrote before.

Your friendly words are worth their weight in gold.") LETTER 13.

TO J.D.HOOKER.