His positions at Columbia University and the American Museum of Natural History were used to develop and train several generations of students . His positions at Columbia University and the American Museum of Natural History he used to train and develop several generations of students .
Kedudukannya di Columbia University dan Muzium Sejarah Alam Amerika digunakan untuk membangun dan melatih beberapa generasi pelajar. Kedudukannya di Columbia University dan Muzium Sejarah Alam Amerika yang digunakannya untuk melatih dan membangunkan beberapa generasi pelajar.