Let me come to [George Gaylord] Simpson. He was the third person in New York interested in evolution. I'm speaking now the time after 1939 when Dobzhansky had come, and he was my colleague at the American Museum [of Natural History]. In fact, when I came in 1931… Simpson was on the staff and we very often ate at the same staff table. We had a staff table where we ate and where I always had very vigorous and interesting and stimulating conversations with other members of the staff. But Simpson never participated. He was very silent and when many, many years later when I was already here in Harvard somebody once asked me and said, ‘Now, you must have had some very interesting conversations with Simpson, both of you sitting at the same staff table for so many years’. And I thought about it, and by God, I couldn't think of single one, and I felt a little uncomfortable about that. So I wrote a letter to Simpson which is in my file somewhere, and I said what about that, is… what… what is your impression? And he wrote back, ‘Yes, you're quite right, we never had any scientific conversations’. Now, Simpson was the kind of person who shunned having scientific discussions and the students would complain about that. In fact, he had very few students, he didn't want to have students. When he came to Harvard we thought well, he… later on he came to Harvard after he had the fall out with the director of the American Museum, we thought he would establish a fine school of students now, but he refused to accept any students, and so he was in Harvard for a number of years without ever having acquired a single student.