Serial punch biopsies of skin of patients with primary and secondary myxedema were subjected to histochemical study and were found to contain deposits of mucinous material in both groups. Treatment with thyroid extract caused a reduction in the amount of these substances in 3-5 weeks. Withdrawal of treatment produced reappearance of the deposits. The findings in the patients with pituitary myxedema were the same as in those with primary thyroidal myxedema.