In the period following the papers on instability among the hot stars of low luminosity, Dr L. Gratton presented a brief account of work in progress on η Carinae by Dr Platseck, Miss Ringuelet, and himself at Córdoba and La Plata. The bright line spectrum of η Carinae is being studied in detail; one interesting observation is that the emission lines of Ti 11 are quite weak as compared to their intensities in novae of comparable excitation. The Balmer lines are also faint. The hydrogen emission lines consist of fairly wide structures upon which are superimposed narrow emission cores, as well as absorption features. The La Plata workers find that the narrow emission lines originate in the nuclear star, while the bright lines that arise from the nebulosity in the immediate vicinity are very wide, their breadths corresponding to a velocity range of 500 to 1000 km./sec. The radial velocities vary greatly from one part of the nebula to another. Gratton and his colleagues believe that η Carinae is actually a member of the Carina O-association upon which it is seen superimposed. The corrected distance modulus of this complex is 12.3 magnitudes, with an uncertainty of less than half a magnitude. It follows that η Carinae at its maximum in 1843 had an absolute magnitude almost certainly exceeding −13, and even now is a fairly luminous object of M = −5 or −6. The La Plata astronomers believe it to be improbable, therefore, that η Carinae is a nova-like variable or a super-nova, but think rather that the object is to be regarded as similar to S Doradus or Hubble's variables in extragalactic nebulae. They comment on the probable membership of both S Doradus and η Carinae in O-associations, and suspect that this connexion may be of great evolutionary significance.