THE STRUCTURE AND METABOLISM OF A CRUSTACEAN INTEGUMENTARY TISSUE DURING A MOLT CYCLE

1. The morphological changes undergone during the molt cycle by the integumentary tissue of the land crab, Gecarcinus lateralis, have been described. 2. The time course of limb regeneration and gastrolith formation has been correlated with the morphological changes of the integumentary tissue. The period of premolt activity during which limb regeneration and gastrolith formation occurs precedes the changes in the integumentary tissues and has, therefore, been called DO. 3. The oxygen consumption of the integumentary tissues has been measured at each stage of the molt cycle. It has been found to increase at the time of synthesis of the exocuticle. The effects of cyanide, dinitrophenol and added substrates on the oxygen consumption of the integumentary tissue have been studied.