[Morphometric observations on the number of neurons in spinal ganglia]

Nerve cell number has been determined in the thoracic spinal ganglia XVII to XXII of chick embryos of 14-18 days of incubation. It is shown that these ganglia constitute a statistically homogeneous population in respect of the number of their constituent nerve cells. The statistical frequency distribution of the thoracic spinal ganglia according to the number of their neurons is unimodal, but markedly asymmetrical with a distinct positive skewness; the distribution differs significantly (P less than 0.05) from a normal (Gaussian) distribution.