Symposia and several review papers have recently been devoted to H II Regions (see e.g. the Mittelberg Symposium on H II regions and Related Topics 1975; the I.A.U. Symposium no.75 on Star Formation 1977; Mezger 1978a, for a discussion of the properties of the interstellar matter; Brown et at. 1978, for the interpretation of radio recombination lines emitted by H II regions; Woodward 1978, for the mechanisms capable of creating stars and Panagia 1978, for the IR emission of dust associated with H II regions).