RESUMO
At the turn of the nineteenth and twentieth centuries, the landscape of emerging experimental embryology in the United States was dominated by the Canadian Frank Rattray Lillie, who combined his qualities as scientist and director with those of teacher at the University of Chicago. In the context of his research on chick development, he encouraged the young Marian Lydia Shorey to investigate the interactions between the central nervous system and the peripheral structures. The results were published in two papers which marked the beginning of a new branch of embryology, namely neuroembryology. These papers inspired ground-breaking enquiry by Viktor Hamburger which opened a new area of the research by Rita Levi-Montalcini, in turn leading to the discovery of the nerve growth factor, NGF.