34 PAPERS, ETC. 



the most kind and valuable assistance from various corres- 

 pondents. Several of them are already mentioned by 

 name, or their publications are quoted. But I wish to re- 

 cord my obligations more especially to Mr. Albert Way, 

 who was my predecessor in this field of research, and has 

 generously assisted rae to tbe ntmost of bis ability. 



