Insights into neural crest migration and differentiation from experimental embryology.

In this essay, I discuss two studies published in the Journal of Experimental Embryology and Morphology that represent how experimental embryologists began to deal with the issue of the vertebrate body plan. In one such study by Nicole Le Douarin and Marie-Aimée Teillet, the neural crest was unequivocally identified as being the origin of the chick enteric nervous system through careful chimeric experiments and histological analyses. In the second, Michael Rickmann and colleagues showed how to combine immunohistochemical and experimental techniques in a study of the segmental patterning of the spinal nerves of the chick embryo.