From some standpoints it should seem surprising that not all of the OB stars of our Galaxy that can be identified to a feasible limiting magnitude (say 12–13) by conventional objective prism techniques have yet been so identified, but this is in fact the state of our published data. Some people here will recall that such a systematic survey for the northern Milky Way was carried out several years ago jointly by the Hamburg and Warner and Swasey Observatories. Now at the Warner and Swasey Observatory we are extending this northern survey into the southern Milky Way that could not be reached from the north, and we are making this extension as homogeneous as possible with respect to the northern survey.