36 OF NEBULJE. 



distances repel each other, but beyond those distances 

 have they a tendency to gravitate towards each 

 other ? And is it because of these antagonist forces, 

 that stars are found associated together in clusters, 

 and not concentrated into one self-luminous or incan- 

 descent mass ? 



43. Does the form of those nebulae (Fig. 8) point 

 out the direction in space to which they trend ? 

 Does each visible star in its motion of translation in 

 space draw after it the nebula with which each is 

 associated ? 



. FIG. 8. 



NEBOLE WITH ONE VISIBLE STAR. 



44. Do those visible stars, which are so often 

 found associated with unresolved nebulae, determine 

 in any way the forms of those nebulae ? 



45. Has the form of the reticulated nebula (Fig. 

 9) been determined by the position of the visible 

 stars with which it is associated ? 



