Cold Spring Harbor - Meeting of Field Workers - June 23, 1915. Dr. Davenport - at the basis of our study of heredity we have the fact that people are not alike. This fact is due to the varying sources from which individuals get their traits. That is why it is so important in studying individuals to have a field worker. Is important for a physician, especially one studying nervous diseases to know the constitution of his patient & to get this he must have field workers. He can treat the case then with better understanding & the family will be glad to cooperate. Important for physician to get the knowledge of developmental history of patient. Some small, incident may throw much light on case. The two most important factors in studying hereditary behavior are - 1) Study of half sibs - Here we have indiv. in same environment but with different germ plasma. The study of half sibs shows