Experiments on Neuromery in Ambystoma punctatum Embryos
In a series of papers the present author has discussed the nature and significance of the transverse bulges of the central nervous system of vertebrates, long since known as neuromeres. Their formation and further development have been described and it has been shown that they are signs of a proliferation pattern, made up of transverse bands of high mitotic activity alternating with bands of low activity. It has also been demonstrated that the neuromeric pattern is preceded by another pattern of a similar nature, mirrored in the formation of the so-called proneuromeres, and is followed by a third pattern, giving rise to the postneuromeres or transverse bands of migration areas. For further details of these investigations, the reader is referred to Bergquist & Källén (1954). An unsolved question is the nature of the factors that cause the patterning of the mitoses and therefore also the bulging of the brain wall to form neuromeres.