Keller R
Department of Molecular and Cell Biology, University of California, Berkeley 94720, USA.
Dev Dyn. 1996 Mar;205(3):257-64. doi: 10.1002/(SICI)1097-0177(199603)205:3<257::AID-AJA6>3.0.CO;2-H.
A number of fundamental problems in developmental and cell biology were articulated in Johannes Holtfreter's classic papers on tissue affinity and mechanisms of amphibian gastrulation. These problems remain unsolved and would be profitably revisited with modern methods of cell and molecular biology.