( 119 ) 



with the intensity of the galactic light in those same portions. For 

 if really the luminous background of the Milky Way had a highly 

 disturbing intluence, a certain parallelism between the distribution 

 of the galactic light over that girdle (which distribution is very 

 irregular) and the distribution of the nebulae in the same region 

 would manifest itself in this sense that the nebulae, especially the 

 faint ones, are least numerous in those patches Avhere the galactic 

 light is strongest. Table II gives the galactic zone proper between 

 — 10° and -\- 10° gal. latitude (northern hemisphere) divided into 

 areas of 30 degs. in galactic longitude ; the two upper lines show 

 for each area the mean density of nebulae derived from Stratonokf's 

 data ; the lower line shows the mean intensity of the galactic light 

 derived from the table on p. 18 of my "Distribution de la lumière 

 galactique" (Verhand. Kon. Akad. v. Wet. VIII, 3). 



TABLE II. 



llie density of the nebulae and the galactic I'lyjit in the 

 Milky Way compared. 



•180° 90° 0° 



No parallelism is to be detected. 



Other causes which might influence in the same Avay as the 

 "extinction" due to the luminous background of the Milky Way, must 

 be disregarded. Up to now the investigation has yielded nothing in 

 contradiction to the view that the peculiar distribution of the nebulae 

 in the sky results, at least in the main, from their particular real 

 distribution in space. 



Cleveland Abbe tried to e.xplain the paucity of nebulae in the 

 galactic region and the (supposed) increase of their number towards 

 the two Poles of the Milky Way by the supposition that the visible 

 universe consists of systems of which our Milky Way, the two 

 Nubeculae and the nebulae are the individuals, which in their turn 

 are composed of stars and (or) nebulae ; that moreover the galactic 

 plane is nearly at right angles to the major axis of "a prolate ellip- 

 soid" in which all visible nebulae are equally scattered. 



This theory is founded on the supposed symmetrical distribution 



