1333 



dental irregularities or to errors, not so however in the case of the 

 two former ones. This is proved by the fact that in all five regions 

 the 2"*^ gradient is smaller, and the first larger than the others. To 

 all probability the reason for the sniallness of the second gradient 

 must be attributed to the fact that the i-eal difference in the limiting 

 magnitudes is smaller still — so that the influence of overlooking 

 the faintest stars on .S' and .l, is yet stronger — than was ascer- 

 tained and accepted above. On account of this therefore all the second 

 gradients should be somewhat larger. The interval B — A^, the first 

 gradient, does not change in this case, as the countings on B and 

 .4, are absolutely similar. 



The first gradient is larger than the others. Here then is manifest 

 the inflaence of the diMant yulactic condensations, lohich therefore 

 U perceptible in the gradients only after the 13,5'^' magnitude. 



The fact that the gradients in region V do not essentially differ 

 from those of the other regions, allows us to draw some important 

 conclusions. This region must be considered as a weakened extension 

 of the tripartite dark hole that forms its core. The cause of the lacking 

 of stars in this hole, extends gradually weakening, over a wider 

 region. As a first explanation we may admit that this cause consists 

 in a local diminished space-density of the stars, so that there is an 

 actual hole between and in the dense star-clouds that constitute the 

 galaxy. In this case the nearer stai's are not influenced thereby, so 

 they must show no thinning, the brighter stars will l)e relatively 

 more numei-ous than the faint ones, and the gradient must l)e smaller 

 than in the denser regions. Of this the numbers show nothing; the 

 stars from the 10^'' to the 14''' magnitude are all diminished to an 

 equal rate. This would imply that these brighter stars for the greater 

 pai't belong to the galactic clouds themselves and are situated at the 

 same great distance. This supposition, however, is excluded by the 



