1. Andrew, A.: A study of the developmental relationship between enterochromaffin cells and the neural crest. J. Embryol. exp. Morph. 11, 307 (1963).
2. Archer, O.K., Sutherland D.E.R., Good, R.A.: The developmental biology of lymphoid tissue in the rabbit. Consideration of the role of thymus and appendix. Lab. Invest. 13, 259 (1964).
3. Arey, L.B.: The history of the first somite in human embryos. Contrib. Embryol. 27, 233 (1938).
4. Benninghoff, A., Goerttler, K.: Lehrbuch der Anatomie des Menschen, 5. Aufl. München-Berlin: Urban & Schwarzenberg 1960.
5. Bodian, M.: Chronic constipation in children. Practitioner 169, 517 (1952).