1. The spirogram tracings were analyzed for irregularities in pattern in a series of 64 psychoneurotic patients and 24 normal control subjects during periods of induced ideational stimuli. During the second, third and fourth periods, the subjects were directed to think of pleasant, unpleasant, and again of pleasant ideas. During the first period no direction was given, and during the last period the patients were asked to relax.2. The respiratory tracings were analyzed for sighing respirations, minor fluctuations, major fluctuations, and points off an arbitrary line for the upper and lower border of the tracings.3. The most consistent changes were observed on comparing the unpleasant period with its preceding pleasant period. Significant changes were found in all of the items in 43 patients (Group I) with diagnoses of hysteria, anxiety neurosis and reactive depression. In the remaining 21 patients (group II) whose diagnoses were hypochondriasis, compulsion neurosis and questionable schizophrenia, a significant change was found in only two items on com paring the tracings for the unpleasant period and its preceding pleasant period.4. Induced unpleasant ideas were associated with an increase in sighing respirations in both groups of patients and in the control subjects. These changes were significant for patients of Group I and for the control subjects.5. Induced unpleasant ideas were associated with significant increases in patients of Group I in upper minor fluctuations, upper major fluctuations, points off the upper line, and lower minor fluctuations.6. No significant changes were found during the unpleasant period in any of the items for Group II patients and for the control subjects.