1. Serial observations of cutaneous and muscle temperatures were made on patients with paralysis of one lower extremity only to ascertain the chronological appearance of changes in its peripheral circulation after the onset of poliomyelitis.

2. The data were subjected to statistical analysis for the determination of the significance of the alterations in circulation which were found.

3. Significant vasoconstriction in the skin of the paralyzed extremity was not present during the acute phase and appeared only after five to six months from the onset of the disease.

4. When vasospasm first appeared, it was minimal and sporadic; but after six months of the disease, the extremities of those with poor and fair muscles became consistently colder. The only exception in the distal portion of the extremity was the great toe which did not follow the circulatory pattern of the remainder of the extremity.

5. In the paralyzed muscle significant coldness appeared five to six months after onset of poliomyelitis in those groups with moderate and severe paralysis but was not present at any time in the group with mild paralysis.

6. Coldness of skin and muscle showed definite relationship to degree of paralysis.