5 



the number of the stars, their distribution in space, 

 their association in groups, and their common 

 motions. He was not directly concerned with 

 those studies of physical condition and of evolu- 

 tional progress in which we hoped to aid in tracing 



FIG. 37. The Milky Way near 6 Ophiuchi. 



the life-history of stars and stellar systems from 

 their birth to their decay. Could we afford to 

 postpone some of our own investigations, at first 

 sight very different from his, even for the very 

 important purpose of advancing his great under- 

 taking? 



