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Résumé : Introduction. Ten years have passed since the last Congress and so much has been published since then in the field of photospheric and allied phenomena that this can only be a summary and not an exhaustive report. Periodicity of Sunspot Activity. The long period already established by R. Wolf in 1862, has again been investigated by W. Gleissberg (Publ. Istanbul Obs. No. 14, 1941; No. 15, 1941; Z. Ap. 21, 347, 1942; Ap. J. 96, 234, 1942), with the result that the period amounts to approximately 70 years.