Based on data reported here we have concluded: (1) that there is a reduction in per-nucleotide template capacity or rat liver chromatin with increasing concentration of template which is suggestive of product inhibition; (2) that the per-nucleotide template capacity of rat liver chromatin increases to a plateau with increasing enzyme concentration suggesting enzyme saturation of available template; (3) that both shearing and heat denaturation of rat liver chromatin increases its capacity as a template; and (4) that neither the chromatin concentration-dependent decrease in template capacity, the enzyme concentration-dependent plateauing, nor the increased template capacity following shearing or heating are influenced by the age of the chromatin donor. © 1969.