Henslow encouraged his protégé Darwin to assist Sedgwick, and since he himself couldn’t take up the position on HMS Beagle, recommended Darwin for it. He received most of the letters and packages Darwin sent back from the voyage, and wrote to advise him on collecting and preserving specimens (Darwin said that meeting him influenced his career more than any other). He persuaded Cambridge University to buy two full sets of Audubon’s great work, and corresponded with the American naturalist thereafter. The elder Hooker started a collection of economically-important plants with him; the younger Hooker married his daughter.