A brief review is presented of the relevant literature concerning Adie's Syndrome (tonic pupillary reaction and the absence of 1 or more deep reflexes). Three cases are reported. The tonic pupil in every instance is constricted by the instillation of 2.5% Mecholyl chloride in the conjunctival sac. The normal pupil is unaffected by such weak aqueous solns. of Mecholyl. This procedure was 1st descr. by Adler and Scheie in 1941. Its usefulness as a diagnostic test is emphasized.