In the field, Curtis instituted his own methodology, "the twenty-five cardinal points," to amass information on all areas of Indian life and lore, including vocabulary, political and social organization, religious customs, dwellings, food gathering and preparation, geography, games, music and dance, dress, weights and measures, and birth, marriage, and death customs. While Curtis was able to gather significant data on all these subjects, his most important contribution was in the areas of mythology and spirituality, fields in which many others had previously failed to gather information. Curtis often sent assistants ahead months in advance to supplement his extensive pre-field research. Only when Curtis felt sufficiently briefed by both his many assistants, led by W.E. Myers, and the leading Indian scholars, did he begin the actual fieldwork. This depth of understanding was critical to his success. "Word passes from tribe to tribe," added Curtis who was soon dubbed the "shadow-catcher." "A tribe that I have visited and studied lets another tribe know that after the present generation has passed away men will know from this record what they were like and what they did, and the second tribe doesn't want to be left out. Tribes that I won't reach for four or five years yet have sent word asking me to come and see them...there was old Black Eagle, an Assiniboin, ninety years old, who had all of his life refused to talk about his nation to white men. At last he became convinced that his tribe ought to get into the record, and he unbent and he gave me a great amount of valuable information."