THE BIRTH OF THE SUN AND PLANETS 27 



main, out of one vast nebula. The 5,000 stars of the 

 beautiful clusters in Hercules or Centaur appear to have 

 a similar origin. It would at present be much too 

 hazardous to extend the idea further. It is a fascinating 

 speculation to imagine the whole 120 million suns of our 

 system as the outcome of a colossal nebula, but such 

 speculation has no firm grounds. At present the facts 

 point to the separate life story of star after star within 

 that system. Here and there in it are the clouds of 

 matter that will one day be worlds : here and there are 

 the dead worlds that await regeneration. And on one 

 little ball, circling round a somewhat middle-aged sun 

 near the centre of the system, we intelligent beings look 

 out on the mighty drama that is being played around us. 

 But it is now time to return to the rounding of our 

 terrestrial fragment of the nebula into a planet, and the 

 great processions over its surface that have culminated 

 in the appearance of humanity. 



