Quantitative estimation of RNA and nitrogen in differentiating central nervous system of chick.

1. Quantitative estimation of RNA and nitrogen for fore-, mid-, hind-brain and spinal cord of the differentiating central nervous system of chick has been made. It is found that the amount of RNA and that of nitrogen do not remain constant in the various phases of ontogeny. 2. Quantity of RNA and of nitrogen are high in most of the tissues upto 12 days of incubation. 3. Increase in the concentration of RNA usually proceeds that of nitrogen. 4. The observations heve been discussed with respect to differentiation of the central nervous system.