The growth cones of individual neurons traverse long distances during embryogenesis, yet they find their correct targets and make their appropriate synaptic connections. One would like to understand how growth cones know where to go (pathway selection) and in particular, how the growth cones of different cells, confronted with the same environment, are determined to make different and stereotyped choices of which way to go. Results demonstrate that growth cones find their correct targets not by random growth, but rather by an active process of precise pathfinding. This chapter shows that the growth cones of pioneer neurons in the central nervous system (CNS) establish stereotyped axonal pathways. The chapter emphasizes the divergent choices made by the growth cones of two sibling pioneer neurons. Later it shows that the growth cones of later cells follow specific axonal pathways laid down by pioneers, and when confronted with several available pathways, make specific choices of which one to follow. The divergent choices made by the growth cones of two sibling interneurons are also emphasized here. Neuronal specificity results in large part from the ability of each individual growth cone to make a sequential series of pathway choices that take it to its correct target. These results lead to propose the “labeled pathways” hypothesis whereby axonal pathways are differentially labeled, probably by cell surface markers, and growth cones use these labels for guidance. One way to search for these “labels” is to make monoclonal antibodies, and progress made using this approach is discussed in this chapter.