Abstract
On the basis of histological and chemical studies it is concluded that following estradiol administration chromosomal RNA synthesis is enhanced, as the result of which transfer RNA and template RNA activities are increased. The subsequent enhancement of the nucleolar RMA[long dash]the structural RNA of the ribosomes[long dash]appears to be a relatively late event. Finally, since the enhancement of RNA synthesis in the nuclear chromatin is an early result of estradiol action, it is likely that the synthesis of other RNA components and of protein are subsequent responses.