Abstract
The in vivo incorporation of valine-1-C14 into the proteins of various tissues of the Cecropis silkworm during its life cycle and under different physiological conditions was investigated. The rate of incorporation was influenced by the age of the animal, by injury to the animal and by the injection of the molting hormone, ecdyson. Myofibril, mitochondrial and soluble proteins were labeled equally, whereas microsomal protein was more highly labeled.