The important conclusion has been already derived that the majority of the stars in the Milky Way belong to one special type.
The horizontal axis is the Galactic Plane or Milky Way.
It is invisible during the greater part of June, July, December and January, owing to its being then blotted out by the superior light of the Milky Way.
Seeliger, who investigated this ratio for the stars of the Bonn Durchmusterung and Southern Durchmusterung, came to the conclusion (as summarized by Simon Newcomb) that for these stars the ratio ranges from 3.85 to 3.28, the former value being found for regions near the Milky Way and the latter for regions near the galactic poles.
There is here evidence that even among stars of the Durchmusterung (9.5 magnitude), a limit of the universe has been reached, at least in the direction normal to the plane of the Milky Way.