By Jim Tober

In 1983, when Bob was facing treatment for his leukemia, he walked me down the hall to his office where he had drawn a couple of lines on the blackboard—one descending and one ascending, with time on the horizontal axis. 

What exactly the lines represented, I don’t recall, but clearly this graph summarized for Bob what was the best evidence available in deciding whether and when to undergo a marrow transplant. Waiting long enough but not too long was, I think, the bottom line.

Bob was an uncommonly good naturalist and teacher, clearly explaining complex realities with a personal observation, a succinct account of the most recent scholarship, a humorous story. And, he was a first-rate scientist, committed to rigorous, fact-based analysis, whether applied to to the marine rocky intertidal zone (his Ph.D. subject), proper motorcycle gear (a more recent passion), or his own highly consequential medical decision-making.

Forward to 1994/95 and the memorable field trip to Mexico and points south. I recently found my photographs from that trip which, true to form, feature too many images of Mayan sites and not enough of my fellow travelers. But, there are Mallory and Bob, sitting together looking out over the ocean near Tulum. I thought at the time I should capture that lovely scene, which is all the more lovely now.